lab ops- Harr Check list
10 mL of chemical soln spilled in the lab... a. pull the fire alarm b. clean the spill*** c. ask everybody to evacuate the lab (It's classified as a small spill. Use spill kit, check for broken glass, put waste material in biohazard)
good
A nurse draws a tube of blood for testing but is left out for 12 hours what tests can be run or do you reject it? -no coag tests -no LDH or NH3 -no glucose (it's ok if it's in Fluoride tube) -no K or Mg
good
ASCP CEU's required? ASCP CMP's: 36 points every 3 years. 2 points for the major 4 areas, and 1 point for safety CLIA requirement in competency: do it throughout the year, and minimize the impact on workload: 1. Direct observations of routine patient test performance testing 2. Monitoring the recording and reporting of test results 3. Review of intermediate test results or worksheets, QC and records 4. Direct observations of performance of instrument maintenance and function checks 5. Assessment of test performance through testing previously analyzed specimens, internal blind testing samples or external proficiency testing samples 6. Assessment of problem solving skills
good
Absorbance formula: A = 2 - log%T A = log 1/T A = -log T
good
Biosafety level 3 cabinet for Pox virus and viral vectors that pose an infection hazard (CDC)
good
Calibration of centrifuge: tachometer (every 6 months) and stopwatch (check the time every 3 months)
good
Cleaning soln in lab: 10% sodium hypochlorite
good
Control falls out 3 standard deviations, which rule is broken? 1:3s
good
Every other parameter on CBC was ok, (MCV, RDW, RBC, PLT, WBC)... delta failure on HGH is due to what? Choices: Instrument malfunction, tourniquet too tight, ***wrong blood was tested.... -Majority of delta check failures are caused by changes in patient status. However, if multiple delta checks fail on several tests performed on a single patient, there is a strong possibility that the patient or specimen was misidentified
good
Infrared light: 750 nm UV: under 400 nm Visible light range: 400-700 nm
good
Lab Management questions regarding turnaround time -automation inc turnaround time -molecular testing has high throughput and high turnaround time -batch tests are slower than single-piece -POCT has high turnaround time
good
Levey chart showing a trend: open new kit
good
MSDS: -part of hazard communication standard (HCS) -issued by OSHA in 1983 -"right to know law", HAZCOM -to inform employees about chemical hazards and protective measures -written hazard communication plan -Inventory of hazardous chemicals on site -Hazard labeling -(MSDS) for each chemical readily accessible to employees on each shift -Training on initial assignment & when new hazard is introduced
good
Multichannel analyzer: Enzyme controls resulted in 3 SD below the mean and the controls with no enzyme resulted in 2 SD within range. What is causing this? a. controls where left at room temperature*** (or low) b. something about being in deterioration (low temp means low enzyme activity. Can be affected by pH too)
good
Ocular correlations (most common ocular viral disease is Herpes 1 and 2) -ocular piece on the microscope eyepiece is 10x -total magnification for Brightfield: 10x ocular and 40x objective = 400x total magnification
good
PCR: Denature, Anneal, Extend Most frequent error in PCR: nucleic acid contamination Qualitative PCR is for DNA-based viruses Branched chain DNA - Signal amplification
good
Photograph is what you can deny the employer during the interview, or your address? it's a photograph
good
QC question on machine with "no endpoint" Endpoint detection with coagulation instruments: Mechanical- change in electrical conductivity between 2 probes Photo-optical- dec in light transmittance as fibrin forms Chromogenic: inc in light ABS at 405 nm as pNA is cleaved by coag enzyme Immunogenic: inc in light ABS as latex particles with Ab are agglutinated by the Ag
good
Quality assurance: -Correlation studies (verifying new methods) -Preventative maintenance -Function checks (testing the operating system) -Delta checks -Critical values (includes values for: glu, Na, K, Ca, Mg, CO2, phos, bili for neonates, blood gases) -Personal competency test (at hire, at 6 months, then yearly) -Proficiency testing (testing of unknowns submitted by CAP) -SOP
good
Random vs systematic error: -Random error: not a regular error; dirty glassware, wrong pipette, voltage fluctuation, sample error, drug interference. Only one control is off (1:3s or R:4s rule is off) -Systematic error: recurring error; dirty photometer, faulty ISE, evaporation of reagents. Affects all results...trend or shift in Levey chart. (2:2s, 4:1s, 10x rule violations). Requires investigation into the problem
good
Reference ranges are performed on a new methodology to test instrument: ***precision
good
Role of a supervisor: A. Democratic*** B. Autocratic (they are 100% in charge) C. Laissez-faire (they do their own thing)
good
Safety precautions you have to take when a lab personnel is electrocuted. What to do when he/she is "stuck" to the electric source itself? -cut off the power source -stand on an insulating material -wood, plastic to shove them away -do CPR if necessary -dry stuff off
good
Used to clean the skin...70% alcohol, water, ***Betadine For whole blood collection: Povidone-iodine solution (alcohol pads can contaminate a test for blood alcohol level)
good
What is (TP x 100)/(TP + FN) a. Sensitivity*** b. Specificity c. Precision d. Reproducibility -Two methods showing pos and neg result: Pos Neg Method 1 50 98 Method 2 100 90 -I could not remember the choices but it is about if Method 1 is more specific than Method 2 or is Method 2 more sensitive than Method 1. Precision/sensitivity/specificity with true positives, false pos, true negs and false negs Method 1 (true positive 50/100, true negative 100/100) Method 2 ( true positive 78/100, true negative 89/100), you can describe that as Method 1 is more specific than method
good
What is a look-back test procedure in QC that is more than one time out for a particular test? Lookback procedure: previous donor units that are untransfused and are suspected should be quarantined and discarded. Also, patients receiving donations from suspect donors need to be identified and informed of the risk.
good
When introducing a new technique, the Workshop approach is the best approach
good
seNsitivity = TP/(TP+FN) x 100 -false negs yield lower sensitivity sPecificity = TN/(TN+FP) x 100 -false pos's yield lower specificity PRECISION = TP/TP+FP
good
What does a delta check mean when doing automated clinical measurements? -Significant change in patient's lab result compared to previous result (It's a warning programmed into the lab software. It can be because of mislabeling, wrong tube for that test, issue with specimen integrity, or a random error. It must be investigated.) Delta Check: comparison of patient data with previous result (the difference) -checking and reporting Analyzer is set to delta check sodium at +/-7. Of these results, which would delta check? (and yes, there were 2 that would "technically" delta check") Day 1: 137 Day 2: 141 Day 4: 132 Day 5: 137 Day 7: 136 Day 8: 142 Day 10: 134 A) Day 1 B) Day 4 C) Day 8*** D) Day 10
good good good
Hospital is going to buy new equipment how do you know if it is working well? coefficient of variation, SD of difference, regenerating result? Calculate CV, question gave SD and mean and you had to pick which one had the best CV -choose the lowest value (the higher the CV, the more the dispersion of mean) -lower the CV, higher the precision CV*** = SD / mean x 100 Mean of 140 with 2(SD) and falls in 95% What is the range? 110-170
good good good good good
Autoclave sterilization: 121 C (249 F) at 15 psi for at least 15 mins CDC criteria for autoclave quality test: -weekly test with biological indicators (weekly spore test with B. stearothermophilus)
good good
Paired T test: instrument linearity, something about comparing means. Comparison of 2 analyzers Paired T Test: compares two sets of a mean*** - calculates a range of values that is likely to include the population mean of differences (Calc a range of values that includes the population mean of the differences)
good good good
Night shift reconstituted controls using water from the water purifier. Why? (Expired reagents) What would you do if the control you reconstituted were all wacky on all of your analyzers. -Check the H2O you used -used new lots*** -used fresh control Your controls are out of range what could be the cause? Do you continue and process patient samples? -hold patient samples problem is resolved -rerun controls once, if out of range still, run a new vial or lot -If it's still out, recalibrate and run controls -Still out, get assistance
good good good
Flow cytometry (optical light scattering) How does it count the cells? -uses a sample with a known conc of fluorescent beads. The sample runs through until a certain # of beads is counted. Vol of sample can be determined. Cell stream passes through quartz. It flows past a light source and the scattered light is measured at different angles. Provides info about cell vol, complexity, and granularity...Forward scatter- cell vol Side scatter- internal structures Electrical impedance (Coulter counter) measures what? -changes in resistance produced by a blood cell as it passes through the electrical field. Blood cells are not good conductors of electricity, but the diluent is conductive. Height of pulses indicates cell vol. # of pulses indicates cell count Inc results in impedance what is the cause? (whatever would cause an inc in resistance) ***pinching the tubing, reagent, compressor?
good good good I think
Why is it that serum bilirubin is preferably measured than amniotic fluid? -amniotic fluid exceeds linearity of the machine being used -amniotic fluid is more difficult to extract -amniotic fluid has different biological components*** (for amniotic fluid, blood and meconium will interfere) Amniotic fluid cannot be tested for bilirubin on regular chemistry analyzer as serum bilirubin because: A) they are demanding B) they are biochemically different*** C) it is just too turbid
good good
If the stock solution had 9 mL of saline and I add 1 ml of serum making it 1:10. Six test tubes labeled A to F contains 0.5 mL saline in each. I add 0.5 mL of the stock solution to tube A and mix and the add 0.5 mL to tube B and mix and add 0.5 mL to tube C and mix until I reach tube F. What would be the dilution in tube F? -something around 1:200,000 or 1:210,000 A dilution in a tube 1:20 and then you took 2 mL of the dilution and add 3 mL of water, if the result is 120 mg/dL, how many would be the original? -3600 mg/dL I think 1.5 DF x 120 = 180 20 DF x 180 = 3600 Calculating a 3% solution: (v/v)% = vol solute/vol soln x 100 Molarity = mol solute/L soln
good good good
Need to pipette 0.5 mL of specimen, What do you use -Volumetric (for transferring) -Erlenmeyer (for holding liquids and mixing) -Serological pipette*** (for measuring serial dilutions and reagent) Volumetric pipette results were bad - why? ***Improper calibration of pipette -they have a single calibration mark. Pear-shaped pipettes
good good
Wavelength of the spectro was set to 540 nm, but the staff keeps getting erroneous (higher than the normal) transmittance, what seemed to be the problem? I chose halogen quartz as being the problem (Were they using the wrong cuvette?) (Bilirubin is measured in amniotic fluid at 454 nm. Baseline is 365 nm and then 550 nm. Specimen needs to be protected from light. Blood and meconium cause interferences) -quartz cuvettes are used for 220-380 nm (UV) AND 750-2000 nm (infrared) measurements -for 380-750 nm measurements (aka Bili), a borosilicate cuvette with an incandescent tungsten or tungsten-iodide is the light source
good good good good
(Brightfield) microscopy lens measurements: 10x-low power (eyepiece), 40x high power, 50x and 100x oil lenses Phase contrast microscope - Brightfield + phase objective lens (living cells***, unstained specimens***, good for urine sediments, especially hyaline casts) Scanning electron microscope can create a 3D image (for virology)
good good good
Agglutination reaction where particle coated with a known antigen reacts with an antibody? -Precipitation (Latex agglutination) -it's an Immunogenic reaction
good I think
What is the CV if the 80-100 mmol/L is within 2 SD's (choices: 5.5% , 10%, 20%) 2.2% I think CV = 2/90 x 100 = 2.2% Westgard rule: 2 consecutive values where they fall outside +2SD or -2SD: 2:2s
good I think good
