As a general rule, enough blood should be collected to run any test at least three times. This compensates for all of the following, except which?

As a general rule, enough blood should be collected to run any test at least three times. This compensates for all of the following, except which?

• A. Instrument error
• B. Technician error
• C. Transcription error
• D. Improper dilution of a sample

Answer: (C)

The idea is that running a test in replicates helps counteract variability that comes from the measurement process itself. Repetition smooths out random fluctuations from the instrument and from the technique—like small differences in pipetting, timing, or calibration—that can cause slightly different results each time. It also helps you notice if a dilution step was off, because inconsistent results across replicates can signal a prep issue. However, transcription errors are mistakes in recording or labeling results, not mistakes in the measurement. Repeating the assay won’t catch or correct those data-entry or labeling mistakes, which is why transcription error is the one that isn’t compensated by running the test multiple times.

The idea is that running a test in replicates helps counteract variability that comes from the measurement process itself. Repetition smooths out random fluctuations from the instrument and from the technique—like small differences in pipetting, timing, or calibration—that can cause slightly different results each time. It also helps you notice if a dilution step was off, because inconsistent results across replicates can signal a prep issue.

However, transcription errors are mistakes in recording or labeling results, not mistakes in the measurement. Repeating the assay won’t catch or correct those data-entry or labeling mistakes, which is why transcription error is the one that isn’t compensated by running the test multiple times.