Step 1 of 5
Prepare the sample
What happens
Blend the sample and make a series of tenfold dilutions.
Good looks like
The sample is mixed well, so bacteria are spread evenly.
How it goes wrong
Clumps of bacteria go unbroken, so the count understates them.
Who
Technical
The method assumes bacteria are randomly distributed, separate and not clustered or repelling each other. If they stay in chains, read the as an estimate of growth units.
US (August 2023)