NCA Clinical Chemistry
when performing thin layer chromatography procedure, the solvent front moved 10.0 cm. The substance of interest moved 4.0 cm. What is the Rf fro the substance of interest? A. 0.25 B. 0.40 C. 2.5 D. 4.0
B. 0.40 The retention time of a substance or compound is defined as the distance of spot of migration divided by the distance of the mobile phase migration
An aspartate aminotransferase (AST) result obtained on a serum specimen diluted 1:3 is 42 U/L. Which of the following results should be reported? A. 84 B. 126 C. 168 D. 210
B. 126
Calculate the corrected creatining clearance usign these data obtained from a person with a 1.73 body surface area Serum creatinine: 1.3 mg/dL Urine creatinine: 2.4 mg/mL Urine volume: 1000/24 hour A. 119 mL/min B. 128 mL/min C. 139 mL/min D. 167 mL/min
B. 128 mL/min 2.4 X100 = 240 mg/dL (240/1.3)x((1000/24)/60) X (1.73/1.73)
What is the longest time that a urine specimen can remain at room temp before it is no longer considered acceptable for analysis? A. 1 hour B. 2 hours C. 3 hours D. 4 hours
B. 2 hours
Which of the following urine specimens is most useful when screening for glucosuria? A. First morning specimen B. 2-hour postprandial specimen C. 24-hour urine specimen D. Midstream clean catch
B. 2-hour postprandial specimen
Which of the following enzymes provides the best indication of obstructive liver disease (cholestasis) A. amylase B. Alkaline phosphatase C. Aspartate aminotransferase D. lactate dehydrogenase
B. Alkaline phosphatase
Which of the following changes occurs in a serum specimen that is maintained at 4 degrees for 8 hours? A. Amylase activity decreases B. Alkaline phosphatase activity increases C. Lactate dehydrogenase activity increases D. Alanine aminotransferase activity decreases
B. Alkaline phosphatase activity increases
If LDL receptors are nonfunctional due to disease, the plasma level of which lipid would increase the most? A. Fatty acid B. Cholesterol C. Cholesterol esters D. Triglycerides
B. Cholesterol
Which of the following collection tubes is the specimen of choice for the determination of glycated hemoglobin? A. Citrate B. EDTA C. Red top D. Ammonium heparin
B. EDTA
At a pH of 7.4, which of the enzymes listed catalyzes the following reaction? pyruvate + NADH > lactate + NAD A. lactate oxidase B. Lactate dehydrogenase C. Pyruvate Kinase D. Pyruvate decarboxylase
B. Lactate dehydrogenase
The following results are obtained on a fresh, randomly collected urine specimen: pH: 5.5 SG: 1.025 Blood: small Protein: 500 mg/dL Glucose: neg Ketone: neg Bilirubin: neg Urobilinogen: 1.0 mg/dL Leukocyte esterase: neg Microscopic exam: 5-10 RBC/HPF, 2-5 WBC/HPF, 2-5 fatty casts, 0-2 waxy casts Which of the following disorders is most consistent with these results? A. Cystitis B. Nephrotic Syndrome C. Acute pyelonephritis D. Acute glomerulonephritis
B. Nephrotic Syndrome
Which protein test is NOT able to detect immunoglobulin light chains? A. Immunoelectrophoresis B. Reagent strip protein test C. Sulfosalicylic acid precipitation test D. protein coagulates between 40-60 celsius
B. Reagent strip protein test
Which results require additional action before reporting? Macroscopic exam pH: 5.5, SG: 1.020, blood: small, protein: 30 mg/dL, glucose: neg, ketone: neg, bilirubin: neg, urobilinogen: 1.0 mg/dL, nitrate: neg, leukocyte esterase: neg Microscopic exam: 5-10 RBC/HPF, 0-2 WBC/HPF, 0-2 granular casts, few transitional epithelial cells, and few sulfonamide crystals A. blood vs RBCs; test for ascorbic acid B. Sulfonamide crystals; perform confirmatory test and check patient medications C. granular casts; should see larger amount of protein, perform protein precipitation test D. pH and crystal ID; sulfonamide crystals precipitate in alkaline urine
B. Sulfonamide crystals; perform confirmatory test and check patient medications
A serum protein electrophoresis is performed and unexpected results obtained. All protein bands migrated further than usual and the bands were further apart from each other. Which of the following would account for the results obtained? A. the support medium has deteriorated B. a higher voltage was used C. the wrong buffer was used; ionic strength higher than required D. The wrong buffer was used; pH was significantly lower than required.
B. a higher voltage was used An improper buffer would reduce the distance
Blood from a newborn has low thyroxine (T4) and elevated TSH compared to reference ranges for that age. These results are most consistent with A. congenital hypopituitarism B. congenital primary hypothyroidism C. congenital secondary hypothyroidism D. a normal response to pregnancy-induced changes in maternal thyroid function
B. congenital primary hypothyroidism
In an adult, a blood glucose level of 35 mg/dL is A. normal B. dangerously low C. dangerously high D. physically impossible
B. dangerously low
Measurements of urinary human chorionic gonadotropin (HCG) in men can be used to A. diagnose hyporgonadism B. detect testicular tumors C. assess pituitary function D. detect excessive estrogen secretion
B. detect testicular tumors
Hyaline casts are found in increased numbers in the urine sediment A. when the urine is alkaline B. following strenuous exercise C. when examined in bright light D. whenever an abnormal amount of protein is present
B. following strenuous exercise
Review the results Macroscopic exam: pH: 6.0, SG: 1.020, Blood: mod, Protein: 500 mg/dL, Glucose: neg, Ketone: neg, Bilirubin: neg, urobilinogen: 1.0 mg/dL, nitrate: neg, leukocyte esterase: neg Microscopic: 10-25 RBC/HPF (dysmorphic forms present), 2-5 WBC/HPF, 2-5 hyaline casts, 2-5 RBC casts, 0-2 granular casts, few uric acid crystals These results are most consistent with a diagnosis of A. gout B. glomerulonephritis C. pyelonephritis D. UTI
B. glomerulonephritis
Increased serum uric acid is found in each the following conditions except: A. gout B. hypothyroidism C. Lesch-Nyhan syndrome D. renal failure
B. hypothyroidism
A trough blood sample for routine therapeutic drug monitoring is usually obtained A. just after a dose is administerd B. just before the next scheduled dose C. at the calculated peak time after a dose D. one half-life after a dose is administerd
B. just before the next scheduled dose
When drugs containing free sulfhydryl groups are excreted in the urine, they can cause false-positive results for which reagent strip test? A. Blood B. ketones C. leukocyte esterase D. nitrite
B. ketones
When present in the urine, which of the following substances could cause false-positive reagent strip blood results A. Acsorbic acid B. myoglobin C. Free-sulfhydryl drug D. X-ray contrast media
B. myoglobin
Which analyte is most likely to be elevated in a specimen drawn 2 hours after an uncomplicated myocardial infarction? A. CK-MB B. myoglobin C. troponin I D. troponin T
B. myoglobin
Which of the following urinalysis findings include contradictory results that should not be reported? A. pH 5.0, small blood, cystine crystals B. pH 6.0, bilirubin pos, ammonium birurate crystals C. pH 7.0, protein trace, calcium oxalate crystals D. pH 7.5, nitrate pos, amorphous phosphates
B. pH 6.0, bilirubin pos, ammonium birurate crystals
Which of the following is not a criterion for the diagnosis of diabetes mellitus? A. fasting glucose >126 mg/dL B. serum glucose < 40 mg/dL within 3 hr after an oral dose of glucose C. classic symptoms and a plasma glucose >200 mg/dL anytime D. A serum glucose >200 mg/dL at 2 hr after an oral glucose dose
B. serum glucose < 40 mg/dL within 3 hr after an oral dose of glucose
A serum specimen is being analyzed for the activity of an enzyme and the following kinetic data obtained 0 min: 0.020 1 min: 0.200 2 min: 0.315 3 min: 0.395 4 min: 0.435 5 min: 0.480 Select the statement that BEST summarized these results A. readings are satisfactory; calculate the enzyme result B. substrate depletion; repeat the assay using a serum dilution C. The 0-3 min reading are satisfactory;use these for enzyme result calculation D. The 3-5 min readings are satisfactory; use these for enzyme result calculation
B. substrate depletion; repeat the assay using a serum dilution check the rate of change of absorbance
when should the Friedewald equation not be used? A. HDL cholesterol is >40 mg/dL B. triglyceride level is >400 mg/dL C. plasma shows no visible evidence of lipemia D. total cholesterol is elevated based on the age and sex of the patient
B. triglyceride level is >400 mg/dL
The following results are obtained from a 28-year old diabetic patient: Na: 140 (135-145) K: 3.8 (3.5-5.0) Cl: 101 (99-109) Glucose: 215 (70-105) BUN: 25 (10-20) Serum Osmo: 328 (275-295) What is the patient's osmolal gap? A. 8 B. 27 C. 48 D. 52
B.27
A technician is summoned to the emergency room to draw blood on Jane Doe. At the same time, numerous injury victims begin to arrive by ambulances from a multiple car accident. The tech does not want to disturb the now busy ER staff. According to the room board, Jane Doe is in ward D. The tech goes to Ward D and collects blood from the only women present. She is unable to verify that she is actually Jane Doe because the patient does not speak English and has no identification bracelet. However, the women nods approvingly when asked if her name is Jane Doe. The tech labels the bloods specimen Jane Doe and returns to the lab. What should be done next? A.Proceed with testing; woman positively ID'd herself B.Specimen should not be used; positive ID of patient was never made C. Specimen should not be used until an ER staff member comes to the lab to sign a waiver verifying patient ID D.Proceed with testing; "Jane" is a female name an she was the only female present in Ward D, so it must be her
B.Specimen should not be used; positive ID of patient was never made
You need to prepare a 1:4 filution of a serum specimen when using saline before analysis. Which of the following pipetting steps would result in this dilution? A. Pipet 0.5 mL serum, then add 1.0 mL saline B. Pipet 1.0 mL serum, then add 2.0 mL saline C. Pipet 1.5 mL serum, then add 4.5 mL saline D. Pipet 2.0 mL serum, then add 5.0 mL saline
C. Pipet 1.5 mL serum, then add 4.5 mL saline
Which type of microscopy would best aid in the differentiation of RBC from the form of monohydrate calcium oxalate crystals that resemble RBC? A. Darkfield B. Phase-contrast C. Polarizing D. Interference-contrast
C. Polarizing
Which of the following constituents has the greatest effect on serum osmolality? A. Glucose B. Protein C. Sodium D. Urea
C. Sodium
Which of the following sediment components is the best indicator that an infection or inflammatory process is taking place in the kidney and not in the lower urinary tract? A. RBCs B. Bacteria C. WBC casts D. granular casts
C. WBC casts
When using atomic absorption spectrophotometry for calcium quantitation, lanthum or strontium is routinely added to each sample to A. minimize matrix interferences B. Prevent ionization of calcium atoms C. avoid interference from phosphate in the sample D. reduce fluctuations from the hollow-cathode lamp
C. avoid interference from phosphate in the sample
Osmolality measurements determine the A. activity of ions per kilogram of solvent B. grams of dissolved solutes per kilogram of solvent C. moles of dissolved solutes per kilogram of solvent D. equivalents of dissolved solutes per kilogram of solvent
C. moles of dissolved solutes per kilogram of solvent
Urine sediment that contains free fat globules and fatty casts is characteristic of A. a bladder infection B. Fanconi syndrome C. nephrotic syndrome D. acute glomerulonephritis
C. nephrotic syndrome
The following arterial blood gas results are obtained pH: 7.28 pCO2: 53 pO2: 75 HCO3-: 26 These results correlate best with a patient experiencing A. metabolic acidosis B. metabolic alkalosis C. respiratory acidosis D. respiratory alkalosis
C. respiratory acidosis
The amniotic fluid from a 40 year old female is tested and the following results are obtained L/S ratio 1.6 (>2.0) alpha-fetoprotein normal Based on these results, if the fetus were delivered today it could have A. Down's syndrome B. an open neural tube defect C. respiratory distress syndrome D. an increased risk of renal failure
C. respiratory distress syndrome
Which of the following methods is NOT used to quantitate serum albumin? A. Nephelometry B. Electrophoresis at pH 8.6 C. sulfosalicylic acid precipitation test D. Dye-bonding method using bromocresol green
C. sulfosalicylic acid precipitation test
Which of the following statements BEST describes the principle of pO2 measurement used in blood gas samples? A. H+ are generated by a reaction at the electrode surface B. The amount of O2 oxidized to hydrogen peroxide is measured C. the number of electrons used to reduce O2 is measured D. a voltage between the measuring half-cell and a reference half-cell is determined
C. the number of electrons used to reduce O2 is measured
All of the following are acceptable precipitations of urine sediment for microscopic examination except A. filling a chamber of a commercial standardized slide B. over-filling the chamber of a commercial standardized slide C. transferring, using a disposable pipette, several drops of sediment onto a microscope slide and coverslipping D. transferring, using a calibrated automatic pipette, 20 uL of sediment onto a microscope slide and coverslipping
C. transferring, using a disposable pipette, several drops of sediment onto a microscope slide and coverslipping
Which of the following crystals can be present in an alkaline urine? A. cystine B. calcium oxalate C. triple phosphate D. sodium urate
C. triple phosphate
A plasma samle was analyzed using ion selective electrodes (ISE) and the following electrolyte results obtained Na = 140 K = 14.0 Cl = 112 HCO3 = 18 These results are consistent with a specimen that A. is severly lipemic B. is slightly hemolyzed C. was collected in an EDTA tube D. needs to be diluted and reanalyzed
C. was collected in an EDTA tube
Which of the following serum results correlates best with the rapid cell turnover associated with chemotherapy treatment regimens? A. Creatinine of 2.5 mg/dL B. Potassium of 5.0 mmol/L C. Urea nitrogen of 30 mg/dL D. Uric acid of 10.0 mg/dL
D. Uric acid of 10.0 mg/dL chemo destroys cells releaseing RNA and DNA
When using an automated instrument, the amount of carryover between consecutive samples is NOT affected by A. rinsing the probe between samples B. separating consecutive samples in a tubing by air segments C. using a separate reaction chamber for each sample D. Using a serum blank
D. Using a serum blank
A patient with intermittent hypertension has an elevated value for urinary catecholamine metabolites. This result may indicate A. hyperaldoseronism B. Hypercortisolism C. idiopathic hypertension D. pheochromocytoma
pheochromocytoma
Ion-selective electrodes compare the voltage(potential) of the measuring electrode to the A. reference voltage B. resistivity of the sample C. conductivity of the sample D. current required to establish the voltage
A. reference voltage
A patient suffering from an acute hemolytic episode has a total bilirubin of 2.2 mg/dL (0.2-1.1). Based on this information, which of the following conjugated and unconjugated bilirubin results would you expect? order is conjugated (0-0.2)/unconjugated (0-1.1) A. 0.1/2.1 B. 0.5/1.7 C. 1.0/1.2 D. 1.6/0.6
A. 0.1/2.1 Acute hemolytic anemia can result in prehepatic jaundice characterized by increased serum bilirubin due to a process that precedes bilirubin processing by the liver. Despite a healthy liver, its ability to rapidly process additional unconjugated bilirubin presented is compromised. This is reflected by an increased unconjugated bilirubin fraction with a normal conjugated fraction.
When performing a thin layer chromatography procedure, the solvent front moved 10 cm. The substance of interest moved 2.5 cm. What is the Rf for the substance of interest? A. 0.25 B. 0.40 C. 2.5 D. 4.0
A. 0.25
A urinalysis is performed on a specimen from a patient with active diabetes insipidus. Which of the following lab data sets is MOST consistent with this diagnosis? (SG/Glucose/urine volume) A. 1.005/neg/3100mL B. 1.020/neg/2500mL C. 1.005/pos/3500mL D. 1.020/pos/2000mL
A. 1.005/neg/3100mL Diabetes insipidus is characterized by polyuria and polydipsia
To quantitate urinary vanillylmandelic acid (VMA), which of the following specimens should be collected? A. 24-hour urine collection B. First morning urine sample C. Ransom, mid-stream clean catch D. 2-hour urine collection following the midday meal
A. 24-hour urine collection VMA is a metabolite of the catecholamines: epinephrine, norepinephrine, and dopamine. Due to the potential effects of exercise, hydration, and body metabolism on excretion rates, a 24-hour collection is the specimen of choice
Which of the following situations indicates that an instrument problem is present and requires further investigation? A. A series of high anion gaps B. A series of high glucose results C. A series of low urine osmo results D. A series of low urine SG results
A. A series of high anion gaps
Situation: It is 8:00 and you are working in the specimen receiving and processing area of the lab. The following specimens are received. Which requires intervention before proceeding with processing and testing? A. Alkaline Phosphate/EDTA/0730 B. Glucose/sodium flouride/0610 C. Blood Gases/ heparin, in ice slush/ 0735 D. Electrolytes (Na,K)/ lithium heparin/ 0550
A. Alkaline Phosphate/EDTA/0730
The following results are obtained on a fresh randomly collected urine sample pH: 5.5 SG: 1.025/refractometer: 1.027 Blood: trace Protein: 30mg/dL Glucose: 100mg/dL/clinitest: pos Ketone: neg Bilirubin: neg/ictotest: pos urobilinogen: 1.0mg/dL Nitrate: neg Leukocyte esterase: pos Microscopic exam: 2-5 RBC/HPF and 5-10 WBC/HPF Which of the following statements regarding these results is true? A. An abnormal amount of bilirubin is present in the urine B. Ascorbic acid is causing the positive leukocyte esterase C. the blood present is causing the protein result to be positive D. radiographic contrast media is causing the high specific gravity
A. An abnormal amount of bilirubin is present in the urine
Which of the following analytes can deteriorate if a blood specimen is exposed to light? A. Bilirubin B. Calcium C. Cholesterol D. Glucose
A. Bilirubin
A physician suspects that a patient has Cushing's syndrome. Based on this information, which of the following tests would assist in this diagnosis? A. Cortisol level B. Vanillyllmandelic acid level C. Thyroid-stimulating hormone level D. 24-hour creatinine clearance
A. Cortisol level
Which of the following is an initial step in a protocol for troubleshooting an automated method when quality control results are NOT acceptable? A. Repeat analysis of QC materials using fresh aliquot or different vial B. Recalibrate the instrument, then reanalyze controls and patient samples C. change reagents, then repeat analysis using a new lot number of QC materials D. perform periodic maintenance, then recalibrate and reanalyze controls and patient samples
A. Repeat analysis of QC materials using fresh aliquot or different vial
A patient with biliary obstruction has a serum bilirubin assay performed. The bilirubin resulted determined using the Jendrassik- Grof method are as follows: Total Bilirubin - 0.8 mg/dL and Conjugated Bilirubin - 1.0 mg/dL The clinical laboratory tech does not report the results. The results obtained are most consistent with A. a technical error occurring during analysis B. insufficient accelerator added to the total bilirubin reaction C. a reduced reaction time for the conjugated bilirubin reaction D. excess diazo reagent added to the conjugated bilirubin reaction
A. a technical error occurring during analysis
When measuring serum bilirubin, the purpose of adding caffeine-sodium benzoate or dyphylline to the reaction mixture is to A. accelerate the reaction with unconjugated bilirubin B. Stop the reaction by destroying excess diazo reagent C. enable azobilirubin formation with conjugated bilirubin D. shift the wavelength absorbed by azobilirubin for increased sensitivity
A. accelerate the reaction with unconjugated bilirubin
In a CSF sample, which of the following proteins is quantitated to assess the permeability of the blood/brain barrier A. albumin B. IgG C. Transferrin D. Prealbumin
A. albumin
Which one of the following protein fractions, when separted in serum by electrophoresis on cellulose acetate, contains a single protein? A. albumin B. Alpha 1 - globulin C. Alpha 2 - globulin D. beta - globulin
A. albumin
pH 8.6 is used for serum protein electrophoresis so that: A. all serum proteins will have a net negative charge B. all serum proteins will have a net positive charge C. electroendosmosis is avoided D. heat production is minimized
A. all serum proteins will have a net negative charge
The urinalysis reagent strips from four different bottles are evaluated using the current quality control materials. Which bottle of reagent strips is acceptable for use today? A. bottle 1: expiration date is today; QC acceptable B. bottle 2: expiration date was yesterday; QC acceptable C. bottle 3: expiration date is next week; QC not acceptable D. bottle 4: expiration date is tomorrow; QC not acceptable
A. bottle 1: expiration date is today; QC acceptable
When examining "unstained" urine sediment, cellular detail is best when observed using A. bright-field microscopy B. darkfield microscopy C. phase-contrast microscopy D. polarizing microscopy
A. bright-field microscopy
Which of the following formulas is an accurate rearrangement of Beer's law, when using a calibration constant (K)? A. c = A/K B. b = A x K C. A = c/K D. K = (a X c)/A
A. c = A/K
Review the following serum test results Creatinine 2.5 mg/dL (0.7-1.5) Cholesterol 220 mg/dL (<220) Glucose 110 mg/dL (70-110) Urea 40 mg/dL (8-26) Uric acid 6.9 mg/dL (2.5-7.0) These results are most consistent with A. compromised renal function B. impaired glucose metabolism C. diagnosis of gouty arthritis D. increased risk for coronary artery disease
A. compromised renal function
Which of the following tests is not used to assess the kidney's ability to concentrate the urine? A. pH B. Refractive index C. osmolality D. Specific gravity
A. pH
When quantitating serum protein using the biuret reaction, the biuret reagent is reacting with A. peptide bonds in proteins B. tyrosine residues in proteins C. free amino groups in proteins D. ammonia released from proteins
A. peptide bonds in proteins
Which of the following serum samples is satisfactory for alkaline phosphatase measurement? A. sample frozen overnight B. sample refrigerated for 1 hour C. sample with moderate hemolysis D. sample maintained at room temp for 2 hours
A. sample frozen overnight
The following urinalysis results are obtained Glucose by reagent strip: neg Ketones by reagent strip: pos These are most consistent with A. starvation B. polydipsia C. diabetes mellitus D. diabetes insipidus
A. starvation
In which of the following situations will the patient have a "normal" urine level of HCG? A. ten days following the spontaneous abortion B. During the 10th week of a normal pregnancy C. during a molar pregnancy D. during the 3rd trimester of a normal pregnancy
A. ten days following the spontaneous abortion
Which of the following serum protein elecrophoresis patterns is most typical (order: albumin, alpha 1, alpha 2, beta, gamma) A. very low, low, high, low, low B. low, low, high, high, high C. very high, low, normal, normal, low D. normal, high, low, high, very high
A. very low, low, high, low, low Nephrotic syndrome has increased permeability to albumin
If a moderately hemolyzed serum specimen is used for protein electrophoresis, which of the following protein fractions will be elevated? A. Albumin B. Alpha1-globulin C. Beta-globulin D. Gamma-globulin
C. Beta-globulin
What part of a spectrophotometer determines the "b" in Beer's law A=abc? A. Light B. Monochromator C. Cuvette D. Detector
C. Cuvette A = abc is absorbance = (molar absorptivity)(light path)(analyte concentration)
Which of the following enzymes catalyzes the conversion of glucose to hydrogen peroxide and gluconic acid? A. Peroxidase B. Hexokinase C. Glucose oxidase D. Glucose-6-phosphate dehydrogenase
C. Glucose oxidase
A single tube of CSF is received in the lab and the following tests requested: total protein, albumin, IgG quantitaiton, microbial culture, gram stain, leukocyte count, and differential cell count. The specimens should be sent to the various lab in which order? A. Chem, heme, micro B. Heme, chem, micro C. Micro, heme, chem D. Heme, micro, chem
C. Micro, heme, chem
Which of the following devices is used in a spec to determine the wavelengths of light that pass through the sample cuvette? A. Detector B. Light source C. Monochromator D. Photomultiplier
C. Monochromator
Which of the following formulas can be used to calculate serum osmolality A. 2.5 X Na B. Na + K + Cl + CO2 content C. (1.86 X Na) + (1/18 X glucose) + (1/2.8 X BUN) + 9 D. (Na + K) - (Cl + HCO3)
C. (1.86 X Na) + (1/18 X glucose) + (1/2.8 X BUN) + 9
Which of the following sets of urinalysis results, physical appearance and SG, is physiologically possible and indicates a concentrated urine? A. 1.000/colorless B. 1.015/brown C. 1.030/yellow D. 1.050/amber
C. 1.030/yellow
Four calibration solutions were evaluated for use as the daily calibration check for the refractometer at the physiological "upper reference range" for urine SG. Which calibration solution should be selected? A. 1.015 B. 1.025 C. 1.035 D. 1.055
C. 1.035
A serum sample is diluted 1:3 before analysis and the following results are obtained: Total protein - 4.1 and albumin - 1.5. Which total protein concentration should be reported? A. 4.1 B. 8.2 C. 12.3 D. 16.4
C. 12.3
Which set of serum electrolyte result is most likely obtained from a serum with an elevated lactate level? (Order: Na, K, Cl, HCO3-) A. 125, 4.5, 100, 10 B. 135, 3.5, 95, 28 C. 145, 4.0, 90, 15 D. 150, 5.0, 110, 30
C. 145, 4.0, 90, 15 As lactic acid is produced it dissociates into H+ ions and lactate anions. Since the body maintains electrical neutrality, as lactate accumulates, another anion is eliminated. In the case of excessive production of lactic acid, bicarb is used to neutralize and eliminate H+ ions produced.
Identify the results that are NOT in electrolyte balance (order is Na/K/ Cl/CO2 content) A. 125/4.5/100/10 B. 135/3.5/95/28 C. 145/4.0/90/15 D. 150/5.0/110/30
C. 145/4.0/90/15 calculate the anion gap
The normal ratio of bicarb ion to carbonic acid in arterial blood is A. 0.03 : 1 B 1 : 1.8 C. 20 : 1 D. 6.1 : 7.4
C. 20 : 1
Blood and CSF samples were collected from a patient within 30 minutes of each other. Which set of glucose results indicates possible bacterial meningitis? (order: blood, CSF) A. 60 mg/dL, 40 mg/dL B. 100 mg/dL, 60 mg/dL C. 200 mg/dL, 30 mg/dL D. 200 mg/dL, 120 mg/dL
C. 200 mg/dL, 30 mg/dL normal glucose in CSF should be 60-80% of blood
The following data was obtained using a cholesterol method 150 mg/dL Standard: 0.200 Normal Control: 0.200 (mean: 150 +/- 1SD of 15 mg/dL) Abnormal Control: 0.400 (mean: 275 +/- 1SD of 25 mg/dL) Patient: 0.500 The patient's cholesterol result should be reported as A. 60 mg/dL B. 150 mg/dL C. 375 mg/dL D. 500 mg/dL
C. 375 mg/dL
Using the following data, calculate the corrected creatinine clearance Serum creatinine: 1.8 mg/dL Urine creatinine: 2.7 mg/mL Urine volume: 640 mL/24 hr Body surface area: 1.25 m2 A. 41 mL/min B. 67 mL/min C. 92 mL/min D. 132 mL/min
C. 92
The following urinalysis results are obtained on a urine specimen Reagent strip blood: neg microscope exam: 10-15 RBC/HPF Which of the following statements best explains these results? A. the microscopically identified RBCs are really yeast B. Myoglobin is causing a false-negative reagent strip blood test C. Ascorbic acid is causing a false-negative reagent strip blood test D. The microscopically identified RBCs are really monohydrate calcium oxalate crystals
C. Ascorbic acid is causing a false-negative reagent strip blood test
A centrifuge is loaded with patient samples and turned on. It begins to vibrate and dance across the table. Which of the following statements BEST accounts for this observation? A. The brake was left "on" B. The brushes need to be replaced C. The rate of acceleration was too high D. The tubes are not balanced in the carriers
D. The tubes are not balanced in the carriers
Which of the following statements about finely granular casts in urine sediment is true? A. they are indicative of end-stage renal disease B. They are frequently seen when women have trich C. Numerous finely granular casts are diagnostic for acute glomerulonephritis D. A few finely granular casts can be seen in urine from normal healthy individuals
D. A few finely granular casts can be seen in urine from normal healthy individuals
Which of the following specimens usually requires concentration before analysis? A. Urine for osmolality B. Amniotic fluid for L/S ratio C. Plasma for making a protein-free filtrate D. CSF for protein electrophoresis
D. CSF for protein electrophoresis Protein content in CSF is usually low, so it must be concentrated 80-100 fold before electrophoresis
Which of the following measurements usually takes place at room temp? A. pO2 by blood gas analyzer B. Sodium by potentiometry C. Ionized calcium by ion selective electrode D. Creatinine by kinetic alkaline picrate method
D. Creatinine by kinetic alkaline picrate method All other methods need to be in a controlled environment at 37 degrees
Samples for calcium analysis by atomic absorption spectrophotometery should be diluted with lanthanum solution because lanthanum ions A. blank for variations in flame temperature B. blank for variations in lamp intensity C. emit light used as the internal standard D. Enhance dissociation of calcium phosphate
D. Enhance dissociation of calcium phosphate
Which of the following components determines the wavelength of light that will pass through the sample cuvette in a spectrophotometer? A. Detector B. Light source C. Potentiometer D. Monochromator
D. Monochromator
Which of the following situations requires corrective action before proceeding with specimen testing? A. Room temperature of the lab is 25 celsius B. refractometer result obtained using type 1 water is 1.000 C. Temperature of the refrigerator that stores the QC materials reads 2 celsius D. Reagent strip protein result is trace when using negative control material
D. Reagent strip protein result is trace when using negative control material
Which of the following statements about the hexokinase reaction for serum glucose quantitations is TRUE? A. the amount of hydrogen peroxide produced is measured B. During the reaction cupric ions are reduced to cuprous ions C. The reaction generates a green condensation product with o-toluidine D. The couples indicator reaction generates NADPH from glucose-6-phosphate
D. The couples indicator reaction generates NADPH from glucose-6-phosphate
Urine sediment that contains RBC, RBC casts, and protein is characteristic of A. bladder infection B. Fanconi Syndrome C. nephrotic syndrome D. acute glomerulonephritis
D. acute glomerulonephritis In acute glomnerulonephritis, glomerular inflammation and injury alters the permeability of the glomerular filtration barrier such that red blood cells and plasma proteins, particularly albumin, enter the renal tubules. As casts form in the distal tubules, the red blood cells resent are incorporated into the cast matrix
Xanthochromic CSF is an indicator of A. bacteria meningitis B. increased pressure of CSF C. increased protein concentration in CSF D. cerebral hemorrhage
D. cerebral hemorrhage Xanthochromia in spinal fluid is yellow pigmentation caused by the presence of bilirubin. The bilirubin results from breakdown of heme released from erythrocytes after bleeding into the brain of spinal column
Chromatographic separation of a mixture of solutes is based on A. variable solubilites of solutes in the mobile and stationary phase B. spectral differences of solutes in the mobile and stationary phase C. selective degradation of solutes by the mobile and stationary phases D. differential distribution of solutes between the mobile and stationary phases
D. differential distribution of solutes between the mobile and stationary phases
All of the following substances can affect the detection of urine glucose using reagent strips except A. ascorbic acid B. bleach C. free-sulfhydryl drugs D. galactose
D. galactose
In a couples enzymatic method for measuring serum cholesterol, the color change observed during the indicator reaction is dependent upon the generation of A. ATP B. NAD C. Oxygen D. hydrogen peroxide
D. hydrogen peroxide The enzymatic method for measuring total cholesterol incubates serum with cholesterol esterase (to release free cholesterol). Subsequently, cholesterol oxidizes the cholesterol producing hydrogen peroxide. In the presence of peroxidase, the hydrogen peroxide produced oxidizes the reduced dye to form a colored product
Urine preservation by refrigeration can cause A. decreased pH due to glycolysis B. increased bacteria due to proliferation C. photo-oxidation of bilirubin into biliverdin D. increased turbidity due to precipitation of solutes
D. increased turbidity due to precipitation of solutes
When iontophoresis is used to collect sweat for chloride analysis, pilocarpine is used to: A. clean the skin area B. Complex with chloride C. Complete the circuit D. induce sweat secretion
D. induce sweat secretion
Which of the following situations could account for this discrepancy? Lab A 5-10 RBC/HPF and 0-2 WBC/HPF Lab B 25-50 RBC/HPF and 5-10 WBC/HPF A. lab B concentrated a smaller volume of specimen B. lab A centrifuged the specimen twice as long as lab B C. lab B centrifuged the specimen at a lower speed than lab A D. lab A used the brake on the centrifuge when processing the specimen
D. lab A used the brake on the centrifuge when processing the specimen
A physician wants a urinalysis performed on a midstream clean catch urine specimen to evaluate whether a woman has a UTI. Which of the following urinalysis results suggests that a new specimen should be collected? A. Chemical exam: blood pos B. chemical exam: nitrate pos C. physical exam: pale yellow, clear D. microscopic exam: many squamous epithelial cells
D. microscopic exam: many squamous epithelial cells
A maternity patient complains of dysuria during a monthly visit with her doctor. The physician suspects a UTI and requests a urinalysis and urine culture. Which type of urine specimen should be collected from this patient? A. random B. catheterized C. first morning D. midstream clean catch
D. midstream clean catch
Turbidimetric assays for serum lipase measure the A. amount of bile acid produced B. amount of titratable acid produced C. rate of production of NADH D. rate of degradation of triglyceride micelles
D. rate of degradation of triglyceride micelles As the micelles become smaller, they scatter less light and the substrate suspension becomes less turbid. The rate of turbidity reflects the amount of lipase activity
The presence of waxy casts in urine sediment and a fixed urine specific gravity of 1.010 correlates best with A. cystitis B. glomerulonephritis C. Acute pyelonephritis D. renal failure
D. renal failure
A creatinine clearance result below the normal reference range most likely indicated a decrease in A. hepatic blood flow B. hepatic creatinine synthesis C. renal blood flow D. renal glomerular filtration
D. renal glomerular filtration
Which of these sugars cannot be detected in urine using the copper reduction test? A. fructose B. galactose C. arabinose D. sucrose
D. sucrose
During the microscopic examination of a urine sediment, a clinical lab tech observes an entity approximately the size of a WBC that demonstates a "flitting or jerky motion". The entity observed is most likely A. bacterium B. glitter cell C. pinworm D. trichomonad
D. trichomonad
The turbid appearance of lipemic serum is due to an elevated level of A. cholesterol B. HDL C. phospholipids D. triglycerides
D. triglycerides
The following results are obtained from a patient whose admission diagnosis is biliary obstruction Serum conjugated bilirubin: increased Serum total bilirubin: increased Urine bilirubin: positive Urine urobilinogen: increased Which of the results obtained is INCONSISTENT with the admission diagnosis? A. serum conjugated bilirubin B. serum total bilirubin C. urinary bilirubin D. urinary urobilinogen
D. urinary urobilinogen