Bacterial Enumeration and Serial Dilutions

Flashcards based on lecture notes about bacteria enumeration and serial dilutions.

Serial Dilution

A method to dilute a sample to a countable range for bacterial colonies.

CFU/mL

Used to determine the number of viable bacteria in a sample.

How to calculate CFU/mL

Number of colonies on plate x reciprocal of dilution of sample

Ideal range of colonies to choose for accurate bacterial count on a plate

30 to 300 colonies

Colony Forming Unit (CFU)

A unit used to estimate the number of viable bacteria or fungal cells in a sample.

Spread Plate Method

Pouring a sample onto a solid medium and spreading it evenly.

Quebec colony counter

An instrument used to count colonies of microorganisms on a plate.

TNTC

Too Numerous To Count; the bacterial concentration is too high to get accurate counts.

TLTC

Too Low To Count; the bacterial concentration is too low to get accurate counts.