NCA Laboratory Practice
A control has a mean of 5.5 with a standard deviation of 0.5. If the lab is using a 95% confidence interval the control values must fall between A. 4.5-6.5 B. 5.0-6.0 C. 4.0-7.0 D. 5.0-6.5
A. 4.5-6.5
What is the molarity of an unknown HCl solution that has a specific gravity of 1.10 and an assay percentage of 18.5% (AW = 36.5) A. 5.6 mol/L B. 6.0 mol/L C. 6.3 mol/L D. 6.6 mol/L
A. 5.6 mol/L 1.10x10x18.5 = 203.5g/L / 36.5 mol/L
Which of the following has the highest incidence of infectious risk in the clinical lab? A. Hepatitis B. infectious mononucleosis C. AIDS D. Rubella
A. Hepatitis
Which of the following phlebotomy equipment is NOT used in an arterial puncture? A. Tourniquet B. glass syringe C. 18-20 gauge needle D. Heparin solution
A. Tourniquet
The regulations from CLIA 1988 apply to A. all clinical lab in the United States B. hospital labs only C. labs engaged in interstate commerce only D. independent labs only
A. all clinical lab in the United States
the term "contaminated sharps" means A. any contaminated object that can penetrate the skin B. needles only C. needles and lancets only D. dirty broken class only
A. any contaminated object that can penetrate the skin
it is the employer's responsibility to ensure that employees are exposed to level so radioactive substances that are A. as low as reasonably achievable B. minimal so as to not be hazardous to general health C. as non-existent as possible D. below 50 REMs/year
A. as low as reasonably achievable
Which of the following would be included as a pre-analytical factor of lab testing? A. centrifuge speed and time used to prepare patient sera B. frequency of calibration of micropipets C. storage temps of reagent packs used for instrument D. establishment of 95% confidence limits for QC decisions
A. centrifuge speed and time used to prepare patient sera
How should HCl burns of the skin be treated? A. flush with copious amount of water B. flush with 10% sodium hydroxide and copious amount of water C. flush with 5% ammonium hydroxide and copious amounts of water D. rush the victim to the nearest emergency facility
A. flush with copious amount of water
With regard to the NFPA system of labeling hazardous chemicals, the number contained in the blue section of the diamond label represents which of the following hazards A. health B. flammability C. reactivity D. chemical specific hazards
A. health
To obtain better separation of liquid and solid components by centrifugation A. increase the speed of the head B. decrease the radius of the circle inscribed by the revolving head C. increase the length of the tube containing the specimen D. reduce the number of specimens in the centrifuge
A. increase the speed of the head
if a tech performing routine microscopic analysis on unstained urine sediment is to have sufficient contrast and resolution to identify important elements, the microscope must be adjusted by A. lowering the condenser and reducing the light B. lowering the condenser and increasing the light C. raising the condenser and reducing the light D. raising the condenser and increasing the light
A. lowering the condenser and reducing the light
a device that allows computers to communicate via phone lines is a A. modem B. CPU C. RAM D. ROM
A. modem
when developing a clinical teaching module, the instructor must A. provide the student with the opportunity to practice the procedure B. prepare a slide series to reinforce the technique C. plan to use at least three types of audiovisual techniques D. plan to limit the activity to less than one hour
A. provide the student with the opportunity to practice the procedure
A patient with a presumptive diagnosis of primary liver disease has an LD-isoenzyme pattern performed on a fresh serum sample then again on the same sample the following day. Result are as follows Order: LD-1, LD-2, LD-3 ,LD-4, LD-5 Normal control: 26, 36, 20, 10, 8 Day 1: 16, 26, 18, 12, 28 Day 2: 24, 34, 20, 9, 13 The most plausible explanation of these results is that overnight the serum sample was A. refrigerated or frozen B. left at room temp C. left uncapped D. diluted with distilled water
A. refrigerated or frozen
Testing for occult blood in feces should be done on aliquots of excreted stools rather than on material obtained on the glove of a physician doing a rectal exam because A. the exam procedure may cause enough bleeding to produce a positive result B. glove powder has been shown to cause false-positive results C. glove powder has been shown to cause false-negative results D. there is a greater chance of urine contamination of the rectal exam
A. the exam procedure may cause enough bleeding to produce a positive result
Following collection of a fingerstick blood sample and tube centrifugation, hemolysis of the serum is noted. The most likely cause is A. the presence of alcohol at the site of puncture B. failure to clean the finger before collection C. the use of nonsterile collection materials D. "milking" the finger prior to collection
A. the presence of alcohol at the site of puncture
The term computer software consists of A. the program and operating system B. memory, program, and printout C. CPU and program D. all the data stored in volatile memory
A. the program and operating system
Storage of computer data may be done A. with magnetic disc or tape B. on a cathode ray tube (CRT) C. in the central processing unit (CPU) D. on a video display terminal (VDT)
A. with magnetic disc or tape
From the following date, calculate the concentration of the analyte in a serum sample read at 560 nm Absorbance of the unknown sample = 0.325 Absorbance of a 200-mg/dL standard = 0.460 A. 283 mg/dL B. 141 mg/dL C. 130 mg/dL D. 14.1 mg/dL
B. 141 mg/dL (0.460/200)=(0.325/X)
11.0 mg/dL of serum calcium is equivalent to which of the following (atomic weight of Ca is 40) A. 2.6 mmol/L B. 2.75 mmol/L C. 2.9 mmol/L D. 3.15 mmol/L
B. 2.75 mmol/L 11.0 mg/dL = 110 mg/L 1 mmol Ca = 0.040 g/l 110/0.040
A CLT determines that a minimum of 85 mL of working reagent is needed for a procedure. To prepare a 1:5 dilution of reagent from a stock solution, one should measure A. 15 mL of stock solution and dilute to 85 mL B. 20 mL of stock solution and dilute to 100 mL C. 25 mL of stock solution and dilute with 125 mL D. 30 mL of stock solution and dilute with 125 mL
B. 20 mL of stock solution and dilute to 100 mL
A method requires the use of an 8% (weight per volume) solution of NaOH. The available solutions are labeled 1 N, 2N, 2.5N, and 10N. Which solution is equivalent to 8% NaOH (AW: Na = 23, O = 16, H = 1) A. 1N B. 2N C. 2.5N D. 10N
B. 2N mEq/L = (mg/100 mL) x 10 x valence/atomic mass 8% = 8g/100mL or 8000mg/100mL mEq/L = 8000 mg x 10 x valence/40 = 2000 N= 2000mEq/L/1000 mL = 2N
A 200-mg/dL solution was diluted 1:10. This diluted solution was then additionally diluted 1:5. What is the concentration of the final solution? A. 2 mg/dL B. 4 mg/dL C. 20 mg/dL D. 40 mg/dL
B. 4 mg/dL
What is the correct formula to convert degrees Fahrenheit to degrees Celsius A. 5/9(F+32) B. 5/9(F-32) C. 9/5(F+32) D. 9/5(F-32)
B. 5/9(F-32)
A whole blood sample arrives at a lab with the following handwriten information. Which information is incorrectly included on the sample? A. Sally Doe - 604A, 235-01-0001 B. Isolation C. 07/16/94-Dr. McLane D. Call results ASAP 09:30 LLS
B. Isolation All samples should be handled with appropriate blood and body-fluid precautions
Which of the following statements concerning type - I reagent grade water is true A. it is not covered by NCCLS specifications for reagent grade water B. It is recommended for use in procedures requiring minimal interference and maximal precision and accuracy C. It may be used for washing glassware if followed by a rinse of higher reagent grade D. It may be stored for extended periods of time after production without affecting its reagent grade
B. It is recommended for use in procedures requiring minimal interference and maximal precision and accuracy
Which of the following best describes the relation of nephelometry to turbidimetry A. Nephelometry measures the amount of light absorbed by particles in solution, and turbidimetry measures the amount of light transmitted through a solution B. Nephelometry directly measures the amount of light scattered by particles in solution, and turbidimetry measures the decrease in incident-light intensity C. nephelometry measures the amount of light emitted by particles in solution, and turbidimetry measures the amount of light reflected by particles in solution D. Nephelometry measures the amount of light transmitted, and turbidimetry measures the amount of light absorbed
B. Nephelometry directly measures the amount of light scattered by particles in solution, and turbidimetry measures the decrease in incident-light intensity
Ensuring the reliability of all steps of a laboratory procedure requires: A. A serum standard to be used B. Preanalyzed or assessed control material to be used C. Patient samples to be processed in duplicate D. None of the above
B. Preanalyzed or assessed control material to be used
a "dumb" computer terminal can be used to A. run programs to perform specific tasks at the work station B. accept data entry only if the main computer is operating C. download programs from the main terminal D. store data if the main computer is not operational
B. accept data entry only if the main computer is operating
chemicals such as sodium hydroxide and sulfuric acid should be labeled A. poison B. corrosive C. biohazard D irritant
B. corrosive
a test that is used to evaluate an individual's abilities against a predetermined standard is A. norm-referenced B. criterion-referenced C. not valid D. not reliable
B. criterion-referenced
If a ground circuit in an instrument wire is NOT complete A. the instrument will not work B. current leakage may cause a shock to the operator C. the fuse of circuit breaker will blow D. a fire will result
B. current leakage may cause a shock to the operator
to properly use a volumetric pipet calibrated "to deliver", one should A. wipe the outside following delivery of the contents B. drain the contents but do not blow out C. rinse out the contents several times D. drain the contents to the lowest etched mark on the volumetric pipet
B. drain the contents but do not blow out
The device used for capturing data from instruments and processing them without delay is A. modem B. interface C. CPU D. printer
B. interface
An example of a post-analytical function of a laboratory information system is which of the following? A. delta checking B. laboratory report production C. order entry of tests D. patient identification
B. laboratory report production
If a patient is suspected of having whooping cough from Bordetella pertussis, which of the following is considered the best type of specimen to isolate the organism? A. throat swab B. nasopharyngeal swab C. cough plate D. any of the above
B. nasopharyngeal swab
The term that means reproducibility among replicate determinations of a sample is A. accuracy B. precision C. reliability D. standard deviation
B. precision
chemicals exist in varying degrees of purity. For quantitative measurements and preparation of accurate standard solutions, it is important to use pure chemicals labeled as A. technical grade B. reagent grade C. purified D. United States Pharmacopeia
B. reagent grade
The coefficient of variation is the A. square root of the variance from the mean B. standard deviation expressed as a percentage of the mean C. sum of the squared differences from the mean D. confidence interval of the mean
B. standard deviation expressed as a percentage of the mean
An automated system that is used for many different analyte applications most frequently has a sample delivery system equipped with a A. fixed pipet B. variable pipet C. selectable pipet D. air-displacement pipet
B. variable pipet
Which of the following has been prohibited from use on anything other than a temporary basis in the lab? A. power strips B. portable floor fans C. extension cords D. multi-outlet boxes
C. extension cords
Blood to be collected from a patient with an intravenous line in the right hand should be taken from which of the following sites? A. Left wrist B. Right wrist C. left arm antecubital D. right arm antecubital
C. left arm antecubital
Statements of observable learning outcomes are called A. goal statements B. performance standards C. objectives D. test questions
C. objectives
Which of the following is essential in stating the conditions of centrifugation in a procedure A. revolutions per minute B. voltage output of centrifuge C. relative centrifugal force D. angle of centrifuge head
C. relative centrifugal force
Which of the following should be performed to determine the optimal wavelength at which to measure the absorbance of a colored solution A. Calibration curve B. wavelength calibration C. spectral transmittance curve D. molar absorptivity calculation
C. spectral transmittance curve
Which of the following instruments is used to measure the speed of a centrifuge? A. Volt-ohm-meter B. refractometer C. tachometer D. potentiometer
C. tachometer
Which of the following statements does NOT apply to dry chemical fire extinguishers? A. they can be used on flammable liquid fires involving live electric equipment B. the can be used on class A, B, and C fires C. they can be used on fires in which a re-ignition source is present D. they contain ingredients that are nontoxic
C. they can be used on fires in which a re-ignition source is present
When there are 5 or 6 consecutive values that continue to increase or decrease on the LJ chart it is called a A. shift B. normal occurrence C. trend D. reliable measurement
C. trend
When collecting a blood sample by means of syringe, hemolysis can be avoided by A. using multiple syringes to permit small-volume collection B. keeping the needle on the syringe during transfer to other tubes C. using a small-bore needle for collection of the sample D. precooling the needle and syringe before collection
C. using a small-bore needle for collection of the sample
What is the proper sequencing of steps for cleansing the venipuncture site when collecting a blood culture? 1. scrub with alcohol 2. scrub with iodine swab 3. allow to dry for 1 minute A. 1,3,2 B. 2,3,1 C. 2,1,3 D. 1,2,3
D. 1,2,3
Which gauge needle would be most appropriate for blood collection if the vein tends to be thready or collapse easily? A. 16 B. 18 C. 19 D. 21
D. 21
A laboratory fire ignited by faulty wiring in a chemistry analyzer and partially fueled by surrounding paper products is classified as A. Class B B. Class C C. Class A and B D. Class A and C
D. Class A and C A = paper C= electric
Calibration of micropipets A. must be verified each day of use B. should be performed gravimetrically with mercury C. is unnecessary if the pipet is certified by the manufacturer D. can be verified spectrophotometrically on a predetermined schedule
D. can be verified spectrophotometrically on a predetermined schedule
A physician request the following test on an EDTA sample: Hb, Hct, BUN, NACl, Glu, Ca, creatinine kinase, and Fe. Of the requested tests, which of the following combinations CANNOT be accurately analyzed on the EDTA specimen? A. Hb, Hct B. BUN, Glu C. Hct, NaCl D. creatine kinase, Ca
D. creatine kinase, Ca
Application of a tourniquet fro linger than 3 minutes during venipuncture will result in A. decreased hemoconcentration around the puncture site B. no changes in blood composition if fist pumping is avoided C. significant decrease in total protein D. increased filtration pressure across capillary walls
D. increased filtration pressure across capillary walls
The most environmentally acceptable method for disposal of most chemical waste products is A. burial B. disposal to a sewer system C. incineration D. listed in the appropriate MSDS
D. listed in the appropriate MSDS
Polystyrene containers are unsuitable for specimen transport offsite because they A. cannot be completely sealed B. are not inert and may interact with the specimen C. allow to must light exposure to the sample D. may crack when exposed to freezing temps
D. may crack when exposed to freezing temps
The aperture diaphragm of a microscope A. reduces stray light B. gathers and focuses the illumination light onto the specimen C. provides the secondary-image magnification of the specimen D. regulates the angle of light presented to the specimen
D. regulates the angle of light presented to the specimen
various blanks may be run during spectrophotometric analysis to correct for absorbance contributed bu entities of the test system other than the actual color reaction. Which of the following blanks is used to compensate fro absorption of the color of the test sample before reagents are added? A. reagent blank B. water blank C. alcohol blank D. sample blank
D. sample blank
Given the following objective, determine the best audiovisual aid to augment learning: "Following instruction, the student will be able to correctly interpret a Gram-stain on a sputum specimen" A. chalkboard B. overhead projector C. videotape D. slides
D. slides
A sample is drawn off-site for transport to a central lab, with glucose, urea, nitrogen, and electrolytes. The anticoagulant of choice is A. sodium fluoride B. potassium citrate C. lithium heparin D. sodium iodoacetate
D. sodium iodoacetate
The wavelength in the ultraviolet region are A. 620-700 nm B. over 700 nm C. 400-450 nm D. under 380 nm
D. under 380 nm
Which of the following does the most to minimize aerosol production during centrifugation? A. using a refrigerated centrifuge B. using centrifuge tubes with tapered bottoms C. selecting centrifuge tube sized that will fit securely into the centrifuge rack D. using stoppered centrifuge tubes or a cover over the rotar chamber
D. using stoppered centrifuge tubes or a cover over the rotar chamber
Which of the following procedures is most basic and effective in preventing the spread of infectious diseases in the hospital environment? A. wearing face masks and gloves in the presence of patients B. wearing lab coats in patient rooms C. wearing lab coats in the lab D. washing hands between each patient contact
D. washing hands between each patient contact
OSHA requires employers to have policies and procedures regarding precautions to take when working with blood and body fluids. This is called a(n) A. universal precaution plan B. chemical hygiene plan C. exposure control plan D. infectious disease plan
C. exposure control plan
A hematology lab in a hospital has determined that the abnormal low RBC control has a mean value of 3.12 million red cells per mm^3. The 95% confidence limits include red cell count values from 3.06-3.18X10^6/mm^3. One standard deviation for this control is equal to A. 0.01X10^6/mm^3 B. 0.02X10^6/mm^3 C. 0.03X10^6/mm^3 D. 0.04X10^6/mm^3
C. 0.03X10^6/mm^3
One nanometer is equal to A. 10^-2 meter B. 10^-6 meter C. 10^-9 meter D. 10^-12 meter
C. 10^-9 meter
If a test has a specificity of 98%, it results in approximately A. 98% false-pos B. 98% false-neg C. 2% false-pos D. 2& false-neg
C. 2% false-pos
a 4.0 mg/dL creatinine standard is needed. To prepare 100 mL of the working standard, how much stock standard of 1 mg/mL creatinine is needed? A. 0.1 mL B. 0.4 mL C. 4 mL D. 40 mL
C. 4 mL 1 mg/mL = 100 mg/dL (4.0mg/dL)(100mL) = (100 mg/dL)(X)
what is to total magnification produced when using a 10X ocular lens and a 40X objective lens on a light microscope? A. 4000X B. 800X C. 400X D. cannot be determined without additional information
C. 400X
A substance-of-abuse specimen has been sent to the lab for cocaine analysis. If there is a possibility that this result will be used in a medical legal investigation, which of the following procedures should be used? A. the phlebotomist draws the blood and takes the specimen to the nurses' station for delivery to the lab B. a chain-of-custody form is completed and the specimen is sent to the lab with the other specimens from the floor C. A chain-of-custody form is signed for each stage of specimen transfer, analysis, and reporting of the result D. No special procedure is needed as long as the specimen is analyzed by the lab personnel collecting the specimen
C. A chain-of-custody form is signed for each stage of specimen transfer, analysis, and reporting of the result
Which federal law removed the exemption of nonprofit hospitals from engaging in collective bargaining with employees? A. OSHA 1970 B. CLIA 1967 C. Amendment to National Labor Relations Act 1974 D. Amendment to Federal Labor Standards Act 1963
C. Amendment to National Labor Relations Act 1974
Which of the following statements best describes the principle of dark-field microscopy? A. transparent objects are rendered visible by changing the amplitudes of light waves as they pass through the objects under study B. selective absorption produces a visible image because specimen detail appears as differences in color to which the eye is sensitive C. Light passes through the specimen at an angle, is diffracted, and enters the objective lens, producing a bright image D. A visible image is produced by the use of magnetic fields, making possible greater magnification and resolution
C. Light passes through the specimen at an angle, is diffracted, and enters the objective lens, producing a bright image
Quartz of plastic cuvettes of optical quality should be used when performing spectrophotometric assays in the UV region because the usual borosilicate glass A. refracts light at 340 nm B. contributes to light scatter at 340 nm C. absorbs light at 340 nm D. emits light of a different wavelength
C. absorbs light at 340 nm
Which of the following statements is a description of a reference interval? A. 95% of the quality control specimens for an albumin method are expected to give a value from 2.6-3.7 mg/dL B. two methods for sodium, when compared, have a correlation coefficient of 0.976 C. analysis for creatine kinase from 95% of patients without muscle cell damage will show results from 15-160 U/L D. the predictive value of the assay for PSA is 59.4% when sensitivity is 79%, specificity is 46%, and disease prevalence is 0.5%
C. analysis for creatine kinase from 95% of patients without muscle cell damage will show results from 15-160 U/L
CLIA requires that personnel be assessed A. quarterly B. semi-annually C. annually D. bi-annually
C. annually
Collection of a 24 hour urine includes which of the following procedural steps A. inclusion of urine specimens at the beginning and end of the timed period B. discarding any urine specimen that is collected at the same time as bowel movement C. collecting each void in a separate container without preservative and then emptying it into the larger container D. removal of aliquots for analysis before collection is complete as long as the volume removed is noted and corrected in the final total volume
C. collecting each void in a separate container without preservative and then emptying it into the larger container
If a timed urine specimen is required for analysis, the patient should be instructed to complete which of the following for the first voided specimen? A. collect and save the sample B. discard the first and the last sample C. discard the first specimen and begin the timing of the urine collection D. it doesn't matter if the first specimen is collected as long as the timing is accurate
C. discard the first specimen and begin the timing of the urine collection
