Membrane filtration technique

Definition

Membrane filtration technique is a microbiological method used to separate and count microorganisms in a liquid sample by passing it through a membrane filter. The retained microbes are then cultivated on appropriate media for identification and enumeration.

5 Must Know Facts For Your Next Test

1. Membrane filtration is commonly used to test water quality and detect bacterial contamination.
2. The pore size of the membrane filter typically ranges from 0.2 to 0.45 micrometers, small enough to trap bacteria.
3. Sterilization of the equipment and proper aseptic techniques are crucial to avoid contamination during the procedure.
4. After filtration, the membrane is placed on a selective or differential agar medium that supports microbial growth.
5. Incubation conditions such as temperature and time are tailored based on the type of microorganism being detected.

Review Questions

Related terms

Selective Media:

Culture media designed to suppress unwanted microbes and encourage desired ones.

Colony Forming Unit (CFU): A measure used in microbiology to estimate the number of viable bacteria or fungal cells in a sample.

Aseptic Technique:

Procedures performed under sterile conditions to prevent contamination by pathogens.