Culture Media used in a Microbiology Laboratory
Here is a list of culture media used in microbiology laboratory, which is based on the mode of action:
Liquid medium
A liquid culture medium consisting of an aqueous solution of one or more constituents (eg. Buffered Peptone water, Nutrient Broth, Tryptone Soya Broth and so forth).
Solid culture medium
A culture medium containing solidifying or gelling agent (eg. agar-agar) in concentrations varying from 1 to 2 %.
Semi-solid culture medium
A sloppy semi solid medium containing 0.15 % of agar-agar. Commonly employed for motility testing (eg. SIM Agar) or using motility as a selective agent (eg. MSRV).
Culture media by intend of use
The composition of a culture medium formulation determines its purpose.
Preservation medium
A preservation culture medium preserves and maintains the viability of microorganisms over an extended period. During long-term storage the preservation medium protects microorganisms against the adverse influences (eg. Dorset egg medium).
Resuscitation medium
A resuscitation medium is a non selective nutrient rich medium enabling stressed, damaged and injured cells to repair and to recover their full capacity for normal microbial growth (e.g.Tryptic soya agar with 0.3 % yeast extract or Tryptic soy broth).
Enrichment medium
A liquid culture medium provides nutrients for rapid multiplication of microorganisms (eg. Buffered peptone water or Nutrient broth).
Fermentation medium
A liquid culture medium formulated to achieve the nutrients for an optimal yield of specific microorganisms (eg. Yeast) or metabolism product (eg. toxin).
Selective enrichment medium
A selective enrichment medium is formulated to support the multiplication of target microorganism or a group of microorganisms whilst partially or totally inhibiting the growth of accompanying interfering organisms (eg. Muller-Kauffmann Tetrathionate broth with novobiocin for salmonella or L-PALCAM broth for listeria).
Isolation medium
A solid culture medium that supports the growth of microorganisms (eg. Plate Count Agar).
Selective isolation medium
A selective isolation medium which supports the growth of specific target microorganisms, whilst inhibiting other interfering microorganisms (eg. PALCAM agar for selecting listeria or MacConkey agar).
Differential medium
A culture medium which permits the testing of one or more physiological / biochemical characteristics of a microorganisms for their identification (eg. Simmons Citrate Agar).
Identification medium
A culture medium designed to produce a specific identification reaction that does not require any further confirmatory test (e.g.Triple Sugar Iron (TSI) Agar).
General-purpose media
Some culture media may be assigned to several categories. Blood Agar, for example can be used as a resuscitation medium, as isolation medium or as a differential medium for the detection of haemolysis.
