Tryptone Salt Broth

Intended Use

Recommended for preparation of specimens, stock suspensions and decimal dilutions for the purposes of microbiological tests. The composition and performance criteria are in accordance with ISO:1999 ISO/DIS 6887-1:2017.

Composition**

ISO :1999 ISO/DIS 6887-1:2017 Specification - Peptone salt solution

M1500I - Tryptone Salt Broth

**Formula adjusted, standardized to suit performance parameters

# Equivalent to Enzymatic digest of casein

Directions

Suspend 9.5 grams in 1000 ml purified/distilled water. Heat if necessary to dissolve the medium completely. Dispense into tubes or flasks as desired. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.

Principle And Interpretation

Tryptone Salt Broth is recommended by ISO Committee (1) for preparation of specimens, stock suspensions and decimal dilutions used in various microbiological tests of food specimens. Tryptone provides nitrogenous compounds and other essential growth nutrients. Sodium chloride maintains the osmotic equilibrium.

For ten-fold serial dilutions, dispense the diluents in volume necessary for the preparation of the decimal dilutions into test tubes or flasks in quantities such that after sterilization each tube or flask contains 9.0 ml. Transfer 1 ml of the initial suspension by means of a pipette into a tube containing 9 ml of sterile diluent at the appropriate temperature. For optimal precision, avoid any contact between the pipette containing the inoculum and the sterile diluent. Mix thoroughly to obtain dilutions until the appropriate number of microorganisms has been obtained.

Type of specimen

Food samples

Specimen Collection and Handling

Processesing : (1)

For processing refer ISO :1999 ISO/DIS 6887-1:2017.

Warning and Precautions

Read the label before opening the container. Wear protective gloves/protective clothing/eye protection/face protection. Follow good microbiological lab practices while handling specimens and culture. Standard precautions as per established guidelines should be followed while handling specimens. Safety guidelines may be referred in individual safety data sheets.

Limitations

1. Individual organisms differ in their growth requirement and may show variable growth patterns on the medium.
2. Each lot of the medium has been tested for the organisms specified on the COA. It is recommended to users to validate the medium for any specific microorganism other than mentioned in the COA based on the user’s unique requirement.

Performance and Evaluation

Performance of the medium is expected when used as per the direction on the label within the expiry period when stored at recommended temperature.

Quality Control

Appearance: Cream to yellow homogeneous free flowing powder.

Colour and Clarity of prepared medium: Colourless to pale yellow coloured clear solution without precipitate.

Reaction: Reaction of 0.95% w/v aqueous solution at 25°C. pH : 7.0±0.2

pH: 6.80-7.20

Cultural Response

Cultural characteristics observed after an incubation at 18-27°C for 45 mins to 1hour. Recovery is considered on TSA.

Key : * - Corresponding WDCM numbers

Storage and Shelf Life

Store between 10-30°C in a tightly closed container and the prepared medium at 15-30°C. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle in order to prevent lump formation due to the hygroscopic nature of the product. Improper storage of the product may lead to lump formation. Store in dry ventilated area protected from extremes of temperature and sources of ignition. Seal the container tightly after use. Product performance is best if used within stated expiry period.

Disposal

User must ensure safe disposal by autoclaving and/or incineration of used or unusable preparations of this product. Follow established laboratory procedures in disposing of infectious materials and material that comes into contact with sample must be decontaminated and disposed of in accordance with current laboratory techniques (2,3).

Reference

1. International organization for standardization (ISO): 1999, Draft ISO/DIS 6887-1:2017.
2. Isenberg, H.D. Clinical Microbiology Procedures Handbook 2nd Edition.
3. Jorgensen, J.H., Pfaller, M.A., Carroll, K.C., Funke, G., Landry, M.L., Richter, S.S and Warnock., D.W. (2015) Manual of Clinical Microbiology, 11th Edition. Vol. 1.