When you are troubleshooting, take a systematic approach. Start at the
beginning and ask yourself questions that will help determine the cause
of the problem. Remember, start at the beginning and don\'t panic!!!

## I. Gathering information

A. What were you doing when the problem started?

1\. calibration

2\. testing controls

3\. testing patients

4\. routine maintenance

5\. precision studies

6\. just experimenting/trying something new

7\. nothing

> B. Has this procedure ever worked? Did it work yesterday?

1\. yes

2\. no

3\. sometimes/sort of

C. What has happened since it worked last?

1\. performed preventive maintenance

2\. changed solutions

3\. changed kit or lot number

4\. had a service call

5\. nothing

D. What is not working?

1\. one test

2\. all tests

3\. several tests

4\. one patient

E. What are the symptoms?

1\. can\'t calibrate

2\. not getting any test results

3\. controls are imprecise

4\. controls are not accurate

5\. patients all high/low, positive/negative

6\. don\'t know

II. **Identifying the problem -** Is it most likely the:

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A.  **[Sample -]{.underline}**Patient sample problems can be related to
    a single sample or all samples. If the problem is for a single
    sample, the controls will most likely be OK. Look for the following:

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1.  ID related: wrong patient, mixed up specimen

2.  Collection: wrong tube, bad draw, centrifuged at wrong speed, not
    separated from cells properly

3.  Interferences in sample: hemolyzed, icteric, lipemic, drugs,
    abnormal A/G ratio

4.  Physical interferences in sample: clots, bacteria, cryoprecipitates

5.  Environmental influences: old sample, excessive exposure to air,
    light, or temperature on or off instrument, evaporation

6.  Inadequate sample delivery: short sample, no sample, bubbles in
    sample, delivered to lab wrong

7.  Analyte concentration of sample is out of linear and/or electronic
    range of instrument

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B.  [**Calibrator/control** --]{.underline} Bad calibrators or
    calibration will affect all the patients and controls. You might
    notice high results being affected more. Look for the following:

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1.  Lot number: bad, wrong

2.  Material: manufactured incorrectly, reconstituted wrong, composition
    as reported on insert sheet incorrect due to error of assay or
    mislabeling

3.  Improper storage (excessive heat, cold, time), improper handling of
    reconstituted sample (excessive heat, cold, inappropriate timeframe)

4.  Calibrators/control in wrong position, wrong type of calibrator or
    control used

5.  Incorrect analyte concentration or ranges specified on the
    instrument

6.  Control organisms not viable

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C.  **[Materials, reagents, media, kits]{.underline} -** Bad materials,
    media, reagents and kits usually affect all tests using them, but
    sometimes the affects are not uniform. Bad reagents can cause
    calibration problems, poor precision, and inaccuracy. Use your eyes.
    Does anything look different? Look for the following:

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1.  Incorrect reagent composition: manufactured incorrectly,
    reconstituted wrong (dilution or diluent)

2.  Improper storage (excessive heat, cold, inappropriate timeframe)

3.  Improper handling of reconstituted reagent (excessive heat, cold,
    inappropriate timeframe)

4.  Incorrect reagent used: reagent put into wrong position

5.  Bad water: bacterial or fungal contamination, wrong pH, bad
    deionizer, bad filters, dirty containers

> D. **[Operator]{.underline}** - Operator problems usually occur in
> time of high workload and stress. Look for the following:

1.  Inadequate training: new testing personnel, new procedure, change in
    procedure

2.  Inadequate knowledge of the technology (doesn\'t understand
    calibration, controls, plating, isolation, etc.

3.  Preconceived bias or outside influence

4.  Unrealistic expectations

5.  Poor technique

> **E. [Instrument]{.underline} -** Usually all controls and patients
> are affected. For instrument related problems, get to know what is
> normal for this instrument or kit. Watch and listen when things are
> going OK. Then you will recognize problems when they occur. Look for
> the following:

1.  Test set up: wrong set up information, incorrect calibrator values,
    wrong units, wrong decimal places, incorrect date and time, wrong
    default settings

2.  Calibration

    a.  Test needs calibration (it\'s time)

    b.  New lot of reagent, new parts or assemblies put on instrument

    c.  Maintenance performed

3.  Software

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a)  Software bug

b)  Rounding error

c)  Incorrect limits set in software

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4.  Mechanical components

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a)  Misalignment of components with use

b)  Failure of components

c)  Loose screws, set screws, hardware

d)  Incorrect set screw adjustment

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5.  Electrical components

    a.  Not plugged in, plugged into faulty outlet

    b.  Connectors plugged in backwards or in the wrong place

    c.  Poor connections due to dirt, cold solder joint, bad sockets, or
        loose components

    d.  Blown fuse

    e.  Broken wire

    f.  Noisy supply voltages, inadequate or improper voltages

6.  Optical components

    a.  Source lamp burned out, improperly mounted, noisy or drifty

    b.  Misalignment of optics

    c.  Dirty mirrors, filter, lamps, cuvettes

    d.  Cuvettes scratched, static electricity, wrong shape, improperly
        manufactured

    e.  Filters delaminated, scratched, cracked, and improperly mounted

> F. **[Problems from other sources]{.underline}**

1.  Expendables

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a)  Pipettes: dirty, cracked, wrong size,

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2.  Maintenance

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a)  Lack of timely maintenance: protein buildup, bacterial
    contamination, blocked probes, and tubing, dirty optics, dirty wash
    bath, dirty waste tubes

b)  Maintenance performed incorrectly: wrong tools or parts, wrong
    solutions, wrong procedure

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3.  Lack of correlation with other methods

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a)  Different methodology

b)  One or both methods not linear

c)  Interferences with one or both methods

d)  Different units

e)  Different blanking

> 4\. Environment

a)  Ambient temperature too high or too low

b)  Ambient humidity too high (condensation) or too low (static
    electricity)

c)  Related to altitude

d)  Vibrations (on same bench with centrifuge)

e)  High airflow (under a vent)

f)  Electrical noise, line noise, bad grounds

g)  Airborne dirt, dust, other pollutants

## III. Fixing the problem

A. Sample problems:

1\. Recollect if only one sample

2\. Examine patient test management system

3\. Repeat test

4\. Dilute

B. Calibrator/control problems

1\. Reconstitute new bottle

2\. Recalibrate/Repeat test

3\. Try a new lot number

4\. Call the manufacturer for help

C. Reagent or materials problems

1\. Reconstitute fresh reagent or try a new kit

2\. Repeat test with fresh reagent, media, etc.

3\. Try a new lot number

4\. Check water, use bottled water

D. Operator problems

1\. Rewrite the procedure for clarity

2\. Conduct training

E. Instrument problems

1\. Check set up parameters

> 2\. Perform maintenance/alignments (be sure everything is clean)

3\. Replace bad part

4\. Recalibrate

5\. Call manufacturer for help

F. Other problems

> 1\. Check out cuvettes, sample cups, electrodes, pipettes, etc., try
> new lots, call manufacturer
>
> 2\. Perform maintenance when due, write procedures clearly

3\. Check method linearity, check units

> 4\. Maintain proper temperature and humidity, position work away from
> drafts and vibrations, keep area clean

IV\. Prove that you have corrected the problem by testing controls
successfully. You will probably want to retest some patients as well.

V. Document what you did to investigate and solve the problem. Tell your
coworkers about the problem and the solution.

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