Before you measure
The five mistakes we see most often, and how to avoid them.
Most of these mistakes give you a wrong number that looks right. Read the linked page for each one before your first sample.
1. Vortex and pipette properly
Vortex until a tornado-like funnel forms in the liquid. If the surface only trembles, keep going. When you pipette small volumes, rinse the tip so no cells stay behind.
A mistake here gives a high coefficient of variation (CV) in your results.
2. Clean every time, deep clean every week
Run Clean after every measurement. Once a week, run Deep clean (15 minutes) and a QC test.
Cleaning prevents carry-over from one sample to the next. The QC test is how you know your setup still performs well, and it keeps CIZE reliable.
See Maintenance schedule.
3. Know if your organism clumps
Some organisms form chains or clumps that a vortex cannot separate, and your BactoBox® counts each one as a single cell. If yours does, break them up before you measure.
A clumped sample reads low.
See Break up cell clumps.
4. Check your medium for background
Some media contain many particles. At low dilutions, such as 1:100, a few may be counted as cells.
Background makes your count read high.
5. Know what cells/mL means
Cells/mL is a direct count of whole cells in the sample you diluted. It is not CFU, and it is not OD. It tracks CFU closely while cells grow.
Keep this in mind when you interpret your data and decide what to do next.
See BacTotal-10.
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