Work out serial dilution plate count instantly with clear inputs, formula shown and shareable results.
Compounds the dilution factor across the serial dilution steps and back-calculates the original viable count from the plate.
Serial dilution
Total dilution = factor per step^number of steps; original CFU/mL = colonies x total dilution / volume plated
Undiluted samples give uncountable plates, and a series guarantees at least one plate in the countable range.
Pipetting error compounds multiplicatively, so a 5% error at each of six steps can shift the result by a third.