【 Principle 】

Protein peptone and yeast extract provide carbon, nitrogen, and trace elements; Lactose is a fermentable sugar; Sodium chloride can maintain a balanced osmotic pressure; Bile salt and crystal violet inhibit Gram positive bacteria, especially Gram positive bacilli and Streptococcus faecalis; Neutral red is a pH indicator.

Main components

Composed of peptone, yeast extract, lactose, sodium chloride, bile salt 3, crystal violet, neutral red, and agar.

Storage conditions and expiration date

Storage conditions: This product should be stored in a dark environment at 2-8 ℃.

Validity period: The unopened original packaging has a validity period of 6 months.

This product is a disposable product.

National standard plate separation and counting: directly coating and counting coliforms in food and water samples to quickly quantify contamination levels.

Microbial testing for water quality: Count the coliform bacteria in purified water, dialysis water, and other water samples to assess the risk of fecal contamination.

Drug and cosmetics inspection: Pour the agar plate to separate and count the coliforms, and determine the hygiene compliance of the product.

Medical environment nosocomial infection monitoring: Quantify the surface coliforms of instruments, countertops, and other environmental surfaces to assess the level of nosocomial infection contamination.

Purification of LST initial fermentation strain: Separate gas producing positive samples by streaking and obtain typical single colonies for biochemical confirmation.

Quantitative verification of disinfection effect: Count the residual coliforms after disinfection and calculate the sterilization efficiency.

Quality control of culture medium performance: Inoculate standard strains to verify the antibacterial effect and color development ability, matched with blank controls.

Escherichia coli

Facultative anaerobic G ⁻ short rod-shaped bacteria, indicator bacteria for fecal contamination, opportunistic pathogenic bacteria, tolerant to bile salts and crystal violet, efficient fermentation of lactose to produce acid; VRBA colony: diameter 1-2mm, deep red/purple red, circular protrusion, with clear red bile salt precipitation ring on the periphery of the colony, smooth edge.

Klebsiella genus (pneumonia/acid producing Klebsiella)

G ⁻ crude short rod-shaped bacteria, thick capsule, commonly found in hospital water and equipment, strong lactose fermentation, pathogenic bacteria under hospital conditions; VRBA colony: The colony is larger, plump, and sticky, with a deep red color. The sedimentation ring is wider and thicker, and the colony is sticky and stringy.

Gas producing Escherichia coli and Enterobacter cloacae

There are Gram negative bacteria with flagella, which are saprophytic bacteria in soil and water sources. They can ferment lactose and grow slightly slower; VRBA colony: Medium red colony, fine sediment ring, dry colony, slightly smaller in size than Escherichia coli.

Fructobacter freundii

G ⁻ bacteria are commonly found in sewage and food, lactose fermentation is delayed, and the color of the 24-hour colony tends to be lighter; VRBA colony: light red to red small colonies with weak precipitation ring, prolonged cultivation and deepening of red color.