Seminar Chemistry Study Module
The coefficient of variation (CV) is: The square root of the standard deviation (standard deviation/mean) x 100 Standard deviation expressed as % of the range of values used to calculate the standard deviation Standard deviation expressed as % of the correlation coefficient
(standard deviation/mean) x 100
A patient sample for uric acid gave an absorbance reading of 0.4; the 50 mg/dL standard used in the test gave an absorbance reading of 0.1. What is the concentration of uric acid in the patient's sample in grams per deciliter? Show your math for full credit.
0.2, unknown/absorbance of unknown= standard/absorbance of standard. Then convert units.
An electrolyte panel was performed on a patient in the emergency room. The following values were reported:Sodium: 150 mEq/L Potassium: 5 mEq/LChloride: 110 mEq/L Bicarbonate: 30 mEq/L The anion gap (without using K) for this patient is: 5 8 10 15 17
10
Reference range for serum Sodium is: 125-135 mmol/L 135-145 mmol/L 110-140 mmol/L 75-100 mmol/L
135-145 mmol/L
BUN values were run for 30 days on a new control.Mean = 15.2 mg/dLStandard deviation = 0.2The 95% confidence limit for this control is a 2 standard deviation range. Which range represents the allowable limits for the control? 14.5-15.5 15.0-15.4 15.2-15.6 14.8-15.6
14.8-15.6
A serum specimen for glucose measurement was allowed to stand unseparated on the clot for 6 hours at room temperature before testing. If the original glucose concentration was 200 mg/dL, what approximate results would be expected after 3 hours? 240 mg/dL No change in results 160 mg/dL 45 mg/dL
160 mg/dL
A creatinine clearance is done on a patient with the following results: Serum creatinine=0.6 mg/dLUrine creatinine= 102 mg/dLUrine volume=1650 mL/24 hoursBody surface area=1.93 m^2 This patient's creatinine clearance, corrected for body surface area is: 93 mL/min 130 mg/dL 175 mL/min 195 mL/min 217 ml/min
175 mL/min
3 mls of water is added to 1 ml of serum. This represents which of the following serial dilution 1:3 1:4 1:5 1:6
1:4
Convert 10 mg/dL of calcium to mmol/L. (mw = 40). Show your math for full credit.
2.5, 10mg/dL * 10deci/L* mole of Ca/40 grams* gram/1000 mg* 1000millimoles/mole
Which of the following results would be the most consistent with high risk for coronary heart disease? 20 mg/dL HDL cholesterol and 250 mg/dL total cholesterol 35 mg/dL HDL cholesterol and 200 mg/dL total cholesterol 50 mg/dL HDL cholesterol and 190 mg/dL total cholesterol 55 mg/dL HDL cholesterol and 180 mg/dL total cholesterol 60 mg/dL HDL cholesterol and 170 mg/dL total cholesterol
20 mg/dL HDL cholesterol and 250 mg/dL total cholesterol
A patient is admitted to the hospital with intense chest pains. The patient's primary care physician requests that the emergency room doctor order several tests, including a lipid profile with cholesterol fractionation. The patient's results are as follows:Total Cholesterol = 400 mg/dL Triglycerides = 300 mg/dLHDL Cholesterol = 100 mg/dL LP Electrophoresis - pending The LDL cholesterol for this patient would be ____________ mg/dL. 160 200 240 300
240 // Total Cholesterol - HDL Cholesterol - (Triglecerides/5) = LDL
What is the reference range for Potassium? 135-145 mmol/L 3.5-5.0 mmol/L 5.0-6.0 mmol/L 12-15 mmol/L
3.5-5.0 mmol/L
Which of the following set of wavelengths is most representative of the visible region? Greater than 950 nm 600-950 nm 350-750 nm 190-350 nm
350-750 nm
Anion Gap is normally: 15-25 7-16 -7 to+17 25-45
7-16
Serum pH reference range is: 7.10-7.40 6.55-7.75 7.35-7.45 7.45-7.55
7.35-7.45
During normal pregnancy, the HCG levels peak at how many weeks after the last menstrual period? 2-4 4-6 9-13 20-24
9-13
Which enzyme is not appropriate for electrophoresis: Alkaline Phosphatase ALT LD CK
ALT
Elevations in which of the following are MOST likely to indicate liver disease? AST, ALT and ALK phosphatase ALK phosphatase, creatinine, and uric acid ALK phosphatase, creatinine, and serum potassium Amylase, AST, ALT, and glucose
AST, ALT and ALK phosphatase
In a spectrophotometric determination, which one of the following is the formula for calculating the absorbance of a solution? (Absorptivity × concentration) / light path in cm (Absorptivity × light path in cm) / concentration Absorptivity × light path in cm × concentration (Light path in cm × concentration) / absorptivity
Absorptivity × light path in cm × concentration
An analgesic that alleviates pain without causing loss of consciousness is: Digoxin Lithium Acetaminophen Phenytoin
Acetaminophen
If serum proteins were immersed in a buffer of pH 8.6, which protein, albumin (pI = 4.7) or gamma globulin (pI = 7.6) would migrate the farthest by electrophoresis, and toward which electrode? Albumin/anode Albumin/cathode Gamma globulin/anode Gamma globulin/cathode
Albumin/anode
An example of a marker of bone formation is: Alkaline phosphatase Urinary N-telopeptide Urinary hydroxyproline Acid phosphatase
Alkaline phosphatase
In the Jaffe reaction, creatinine reacts with: Alkaline picrate solution to yield an orange red complex Sodium nitroferricyanide to yield to a reddish brown color Potassium iodide to form a reddish purple complex Colorless NAPA solution at 340nm
Alkaline picrate solution to yield an orange red complex
Universal Precautions or Standard Precautions should be observed when working with: Hemophiliacs Patients with AIDS Drug users All patients
All patients
What enzyme is produced in the salivary and pancreatic glands? AST Amylase Cholinesterase Acid phosphatase
Amylase
CLIA was established to provide oversight to: Research Labs Waived POC testing Any lab performing patient testing CAP Accredited Labs
Any lab performing patient testing
The glucose value of a NORMAL 2-hour post-prandial serum specimen, as compared to the reference range for a fasting serum glucose, should be: Significantly greater than the normal fasting glucose level Significantly lower than the normal fasting glucose level Approximately the same as the normal fasting glucose level Unrelated to each other
Approximately the same as the normal fasting glucose level
Which of the following genetic markers is associated with breast cancer? Rb BRCA-1 and -2 WT1 CA-125
BRCA-1 and -2
The majority of the iron in whole blood is: Bound to hemoglobin In the free ionized form in plasma Bound to transferrin in plasma Bound to ferritin
Bound to hemoglobin
Hypernatremia commonly occurs in: Burns, syndrome of inappropriate ADH, and excessive sweating without water intake Burns and excessive sweating without water intake Syndrome of inappropriate ADH and nephrotic syndrome Nephrotic syndrome only Burns, syndrome of inappropriate ADH, excessive sweating without water intake, and nephrotic syndrome
Burns and excessive sweating without water intake
The carcinoma-associated tumor antigen most useful for following patients with ovarian cancer is: CA 72-4 CA 15-3 CA 125 CEA
CA 125
When myocardial infarction occurs, the first enzyme to reach peak elevation is: CK LD AST ALT
CK
Which isoenzyme of creatine kinase (CK) is primarily found in cardiac muscle? CK-MM CK-BB CK-MB CK-BC
CK-MB
Of the following drug therapies, which is MOST likely to interfere with the Jaffe chemistry for measuring creatinine? Aspirin Cephalosporin Acetaminophen Urea
Cephalosporin
The buffering capacity of blood is maintained by a reversible exchange process between bicarbonate and: Sodium Calcium Potassium Chloride
Chloride
The buffering capacity of blood is maintained by the reversible exchange process between bicarbonate and: Sodium Potassium Chloride pO2
Chloride
What is the common substrate that all adrenal steroids are produced from? Cholesterol Triglycerides Cortisol Albumin
Cholesterol
The most likely cause for serum/plasma to appear "milky" is the presence of: VLDL LDL HDL Chylomicrons
Chylomicrons
CEA is most commonly associated with: Breast cancer Ovarian cancer Colon cancer Myelocytic leukemia
Colon cancer
Which of the following is NOT commonly used as a tumor marker? Prostate specific antigen Alpha-fetoprotein Carcinoembryonic antigen Cortisol
Cortisol
Measurement of the sodium and chloride concentration of sweat is the most useful test for the diagnosis of: Cystic fibrosis Diabetes mellitus Zollinger-Ellison syndrome Thyroiditis
Cystic fibrosis
The sweat test for chloride is used as a screening test for: Parkinson's disease Cystic fibrosis Pancreatitis Hyper- or hypchloremia Hyperkinetic disorders
Cystic fibrosis
Metabolic acidosis is described as a(n): Increase in HCO3 and pCO2 with a decreased pH Decrease in HCO3 with an increased pH Increase in HCO3 with an increased pH Decrease in HCO3 and pCO2 with a decreased pH
Decrease in HCO3 and pCO2 with a decreased pH
Which of the following is likely to occur first in iron deficiency anemia? Decreased serum iron Increased TIBC Decreased serum ferritin Increased transferrin
Decreased serum ferritin
When finished with lab exercises for the day, which order of events should be followed? Remove gloves, disinfect area, wash hands, remove lab coat Disinfect area, remove gloves, remove lab coat, wash hands Disinfect area, remove gloves, wash hands, remove lab coat Remove gloves, wash hands, remove lab coat, disinfect area
Disinfect area, remove gloves, remove lab coat, wash hands
Which of the following best describes the correct collection and handling conditions for a blood ammonia measurement? Fasting patient, draw clot tube, separate serum immediately, test immediately Draw sodium heparin tube, place in ice bath immediately, separate cells and plasma in refrigerated centrifuge, immediately remove plasma and freeze if analytical testing is delayed Draw clot tube, separate serum from clot in refrigerated centrifuge, protect from light, freeze if not tested immediately Fasting patient, draw lithium heparin tube, place tube on an ice pack, centrifuge at 20° C, test immediately
Draw sodium heparin tube, place in ice bath immediately, separate cells and plasma in refrigerated centrifuge, immediately remove plasma and freeze if analytical testing is delayed
A 21-year-old man with nausea, vomiting, and jaundice has the following laboratory findings:Total serum bilirubin 8.5 mg/dL (normal 0-1.0 mg/dL)Direct serum bilirubin 6.1 mg/dL (normal 0-0.5 mg/dL)Urine urobilinogen IncreasedUrine bilirubin PositiveAST 200 U/L (normal 0-50 μ/L)ALP 160 u/L (normal 0-150 u/L)ALT 200 U/L (normal 7-56 μ/L) What disease state are these findings consistent with? Chronic liver disease Obstructive jaundice Hemolytic anemia Early hepatitis
Early hepatitis
Which of the following elevates carboxyhemoglobin? Nitrite poisoning Exposure to carbon monoxide Sulfa drug toxicity Sickle cell anemia
Exposure to carbon monoxide
True or false? Blood is drawn into a Vacutainer tube and allowed to clot. If the serum is not separated from the cells, the serum potassium will tend to decrease and the serum sodium will tend to increase. True False
False
True or false? Serum urea levels are less affected by diet and metabolism than are serum creatinine levels. True False
False
The most sensitive enzymatic indicator for liver damage from ethanol intake is: Alanine aminotransferase (ALT) Aspartate aminotransferase (AST) Gamma-glutamyl transferase (GGT) Alkaline phosphatase
Gamma-glutamyl transferase (GGT)
The "gold standard" confirmation method for positive drug screens is : Immunoassay High-performance liquid chromatography Gas chromatography/mass spectrometry Ultraviolet absorption spectroscopy
Gas chromatography/mass spectrometry
A diabetic patient is prescribed a daily regimen of insulin. Which of the following laboratory procedures would be of most value in determining the degree of glucose control over a 2-month period? Fasting blood glucose 2-h PP glucose OGTT Glycated hemoglobin Fructosamine
Glycated hemoglobin
Which hormone, produced by the placenta, is used for early detection of pregnancy? FSH HCG LH Progesterone
HCG
Which of the following has the highest incidence of infectious risk in the clinical laboratory? Hepatitis Infectious mononucleosis Acquired immunodeficiency syndrome (AIDS) Rubella
Hepatitis
A very high AFP is most characteristically associated with: Hepatocellular carcinoma Alcoholic cirrhosis Multiple myeloma Active hepatitis
Hepatocellular carcinoma
The reference method for glucose determination is: Glucose dehydrogenase Hexokinase Glucose oxidase Copper-reduction
Hexokinase
Which of the following methods for glucose results in the formation of NADPH for measurement? Glucose oxidase Glucose dehydrogenase Ortho-toluidine Hexokinase
Hexokinase
The most common hemoglobinopathy in the United States is due to a defect in: Hgb S Hgb C Hgb SC Hgb D
Hgb S
A patient is admitted to the hospital with intense chest pains. The patient's primary care physician requests that the emergency room doctor order several tests, including a lipid profile with cholesterol fractionation. The patient's results are as follows:Total Cholesterol = 400 mg/dL Triglycerides = 300 mg/dLHDL Cholesterol = 100 mg/dL LP Electrophoresis - pending This patient's LDL cholesterol is: Optimal Desirable Borderline High
High
If the BUN for a patient is high, the creatinine would be: Low High Normal There is no connection between BUN and creatinine
High
A patient is admitted to the emergency room in a state of metabolic alkalosis. Which of the following would most likely be consistent with this diagnosis? High pCO2, increased HCO3 Low pCO2, increased HCO3 High pCO2, decreased HCO3 Low pCO2, decreased HCO3
High pCO2, increased HCO3
A patient has the following test results: increased serum calcium levels, decreased serum phosphorus levels, and increased levels of parathyroid hormone. This patient most likely has: Hyperparathyroidism Hypoparathyroidism Nephrosis Steatorrhea
Hyperparathyroidism
All of the following are characteristic of severe hyperglycemia EXCEPT: Polyuria Ketonuria Glycosuria Hyponatremia
Hyponatremia
A patient test results show: Decreased Free T4Increased TSHPositive Thyroid peroxidase Ab The patient's most probable diagnosis is: A normal thyroid Hypothyroidism Hyperthyroidism Grave's disease
Hypothyroidism
A blood sample for determination of the trough level of a drug is appropriately drawn: During the absorption phase of the drug Immediately after drug administration During the distribution phase of the drug Immediately before drug administration Two hours after drug administration
Immediately before drug administration
Which of the following statements is NOT TRUE of capillary blood? May be used in place of arterial blood when blood gases are done on an infant Is more similar to venous than arterial blood for concentrations of analytes. May be collected from the fingertip of an adult or heel of an infant Most chemistry analytes are similar to venous blood values except glucose
Is more similar to venous than arterial blood for concentrations of analytes.
An LD flip, in assessing a possible myocardial infarction, refers to: LD2 > LD1 LD5 > LD1 LD1 > LD5 LD1 > LD2
LD1 > LD2
Which of the following lipoproteins is the major carrier of cholesterol to peripheral tissues? Chylomicrons VLDL LDL HDL
LDL
Serum bilirubin is unstable because of: Light sensitivity Precipitation due to acid pH Digestion by proteolytic enzymes Precipitates on standing
Light sensitivity
A carbonate salt of which drug is used to control manic-depressive disorders? Digoxin Acetaminophen Lithium Phenytoin
Lithium
Level I and Level 2 control results obtained for a glucose analysis are more than two standard deviations from the mean. The first thing you would do is: Rerun the control with the same reagents. Discipline the technologist who was responsible for the unacceptable work Call the company to repair the instrument Make new reagents and run the controls again. Check the control expiration dates.
Make new reagents and run the controls again. Check the control expiration dates.
The first step in analyzing a 24 hour urine for any analyte is: Add the appropriate preservative Measure the total volume Screen for albumin using a dipstick Subculture the urine for bacteria
Measure the total volume
What condition does the following results represent? pH= 7.52pCO2= 44HCO3-=39 Respiratory acidosis Respiratory alkalosis Metabolic acidosis Metabolic alkalosis
Metabolic alkalosis
Clinical assays for tumor markers are most important for: Screening for the presence of cancer Monitoring the course of a known cancer Confirming the absence of disease Identifying patients at risk for cancer
Monitoring the course of a known cancer
Face masks and protective eyewear are designed to offer protection from: Needlesticks Clothing contamination Skin contact Mucous membrane contact
Mucous membrane contact
CA125 is likely produced by a malignancy of: Colon Liver Ovarian Pancreas
Ovarian
The three hormones that regulate serum calcium are: PTH, vitamin D, and estrogen PTH, vitamin , and calcitonin PTH, renin, and calcitonin Erythropoietin, calcitonin, and estrogen
PTH, vitamin , and calcitonin
The regulation of calcium and phosphorus metabolism is accomplished by which of the following glands? Thyroid Adrenal glands Pituitary Parathyroid
Parathyroid
Calcium concentration in the serum is regulated endogenously by: Insulin Parathyroid hormone Thyroxine Vitamin D
Parathyroid hormone
TSH is produced by what gland? Thyroid gland Adrenal cortex Pituitary gland Hypothalamus
Pituitary gland
Which of the following electrolytes would be increased in the serum if the blood specimen was hemolyzed? Potassium only Potassium, chloride and phosphate Chloride and sodium Potassium, magnesium and phosphate
Potassium, magnesium and phosphate
The most specific tumor marker for prostatic cancer is: Prostate specific antigen Prostatic acid phosphatase Alpha-fetoprotein Human chorionic gonadotropin
Prostate specific antigen
Which of the following is considered to be a waived test procedure? Rapid Strep A Screen Enzyme-linked immunosorbent assay (ELISA) Blood typing Culture and Sensitivity
Rapid Strep A Screen
What condition does the following set of results represent: pH=7.26pCO2=56HCO3-=24 Respiratory acidosis Respiratory alkalosis Metabolic acidosis Metabolic alkalosis
Respiratory acidosis
The sample of choice for measuring blood osmolality is: Serum Plasma Whole blood Serum or plasma may both be used
Serum
A physician calls the laboratory and asks what lab tests should be requested to assess the acid-base balance function of a patient's renal system. You reply: Serum creatinine, serum urea, serum uric acid, and creatinine clearance Serum bilirubin (conjugated and total), urine urobilinogen Serum bicarbonate and blood pH Serum rennin and erythropoietin
Serum bicarbonate and blood pH
Monitoring of _______ in patients on chemotherapy due to leukemia, lymphoma or multiple myeloma is necessary to avoid nephrotoxicity. Serum creatinine Urine creatinine BUN Serum uric acid Urea in urine
Serum uric acid
Which activity can spread HIV or HBV from one person to another outside of the laboratory? Using a toilet Sexual contact Giving blood Shaking hands
Sexual contact
The solute that contributes the most to serum osmolality is: Sodium Water Glucose Potassium
Sodium
The preferred collection tube for preservation of glucose is: Calcium oxalate Sodium fluoride Lithium heparin Sodium citrate
Sodium fluoride
Which of the following statements describes optimal conditions for transport, handling, and storage of blood specimens for clinical chemistry testing? Specimen brought to lab within 6 hours after collection, stored at room temperature before centrifugation for up to 24 hours Specimen brought to lab immediately, permitted to clot, serum separated and tested as soon as possible Specimen brought to lab immediately, spun down and serum left to stand on clot until tested None of these represent optimal conditions
Specimen brought to lab immediately, permitted to clot, serum separated and tested as soon as possible
Which of the following is the formula for standard deviation? Square root mean Square root of (sum of square differences/N-1) Square root of variance Square root of (mean/sum of squared differences)
Square root of (sum of square differences/N-1)
T4 (Thryroxine) is converted into the more biologically active hormone: TRH TSH Thyroglobulin T3(Triiodothyronine)
T3(Triiodothyronine)
The primary serum test to screen for thyroid disease is: TSH Free T4 TPO antibodies T3
TSH
A drug that relaxes the smooth muscles of the bronchial passages is: Acetaminophen Lithium Phenytoin Theophylline
Theophylline
Which of the following proteins binds ferric iron and is increased in iron-deficiency anemia? Ferritin Transferrin Bilirubin Ceruloplasmin
Transferrin
Which MI marker is the most specific and sensitive and remains elevated for 14 days or more? CK-MB Troponin T LD1 CK-MB isoform
Troponin T
Serum uric acid levels may be elevated in patients undergoing chemotherapy. True False
True
True or false? Chloride is the major extracellular anion in plasma. True False
True
Which of the following does the most to minimize aerosol production during centrifugation? Using a refrigerated centrifuge Using centrifuge tubes with tapered bottoms Selecting centrifuge tube sizes that will fit securely into the centrifuge rack Using stoppered centrifuge tubes or a cover over the rotor chamber
Using stoppered centrifuge tubes or a cover over the rotor chamber
Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are both elevated in which of the following diseases? Muscular dystrophy Viral hepatitis Myocardial infarction Obstructive liver disease
Viral hepatitis
Which of the following procedures is most basic and effective in preventing the spread of infectious diseases in the hospital environment? Wearing face masks and gloves in the presence of patients Wearing laboratory coats in patient rooms Wearing laboratory coats in the laboratory Washing hands between each patient contact
Washing hands between each patient contact
The most common method for measuring Magnesium in serum is colorimetric using: a calmagite method using an ISE an orthocresolphthalein complexone arsenazo dye
a calmagite method
What is the cause of AIDS? a protozoan a bacterium a fungus a virus
a virus
Lipase is ________ specific for acute pancreatitis than amylase and is elevated______________. non, a short time less, a longer time more, a longer time more, a short time
more, a longer time
Which of the following forms of the Henderson-Hasselbalch equation is (are) correct? pH = 6.1 + log HCO3/H2CO3, pH = 6.1 + S x pCO2/HCO3, and pH = pKa + log HCO3/H2CO3 pH = 6.1 + log HCO3/H2CO3 and pH = pKa + log HCO3/H2CO3 pH = 6.1 + S x pCO2/HCO3 and pH = pKa - log HCO3/H2CO3 pH = pKa - log HCO3/H2CO3
pH = 6.1 + log HCO3/H2CO3 and pH = pKa + log HCO3/H2CO3
