Microbial Culture Media

Culture medium

solid or liquid preparting used to grow, transport and store microorganisms

Liquid Media

water-based solutions that do not solidify at temperatures above freezing “broths , milks, infusions”

Semisolid media

exhibits clotlike consistency under ordinary room temperature due to presence of solidifying agent agar or gelatin, use to determine the motility of bacteria, used to determine the motility of bacteria and to localize a reaction at a specific site

Solid media

good for isolating and culturing bacteria and fungi provide a firm surface on which cells can form discrete colonies.

Synthetic

chemically defined composition, contain pure chemical nutrients and molecular content

Nonsynthetic or complex

contains biologically complex, undefined components used for general growth

General purpose media

designed to grow a broad spectrum of microbes that do have special growth requirements

Enriched Medium

contains complex organic subtances such as blood, serum, hemoglobin or special growth factors

Selective Media

contains one or agents that inhibit the growth of a certain microbe or microbes, suppressing the unwanted background and allowing growth of the desired ones

Differential Media

grow several types of microorganism but are designed to bring out visible differences among these microorganisms

Specimen transport Media

used to maintain and preserve specimens that have to be held for a period of time before clinical analysis

Assay Media

used by technologists to test the effectiveness of antimicrobial drugs and drug manufacturers

Enumeration Media

count the number of organisms in milk, water, food, soil and other samples

Inoculation

introducing bacteria into the medium

Incubation

Exposing the inoculated medium to optimal growth conditions

Isolation

separating individual microbes and achieving isolated colonies that can be readily distinguished from one another

Inspection

observing cultures microscopically for appearance and growth

Information gathering

testing of cultures with procedures that analyze biochemical and enzyme characteristics

Identification

analysis of collected data to help support a final determination of the types of microbes present in the original sample

Pure culture / Axenic

container of medium that grows only a single known species of microorganism

Mixed Culture

container that holds two or more differentiated species of microorganisms

Streak plate method

small droplet of culture or sample spread over surface of the medium with an inoculating loop, sample dilutes the more you streak

Pour Plate

sample will be poured into the plate

Serial dilution

series of sequential dilutions used to reduce a dense culture of cells to a more usable concentration

Spread plate

a diluted sample is pipetted onto the surface of the medium and spread around evenly by a sterile spreading tool “hockey stick”