Fluid Lactose Medium w/ Soya Lecithin and Polysorbate 20 (Twin Pack)

Intended use

Recommended for microbial evaluation of oral hygiene products.

Composition**

**Formula adjusted, standardized to suit performance parameters

# - Equivalent to Beef extract

Directions

Suspend 18.0 grams of Part A in 960 ml purified / distilled water. Heat if necessary to dissolve the medium completely. Add 40 ml of Part B. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C. Mix well and dispense as desired.

Principle And Interpretation

Fluid Lactose Medium w/ Soya Lecithin and polysorbate 20 is recommended for microbial evaluation of oral hygiene products(1). HM Peptone B and gelatin peptone provide nitrogen and carbon compounds, long chain amino acids and other essential nutrients for bacterial metabolism. Lactose is the source of fermentable carbohydrate. Soya lecithin neutralizes the quaternary ammonium compounds while polysorbate 20 neutralizes phenolic disinfectants; hexachlorophene and formalin.

Type of specimen

Oral hygiene product samples

Specimen Collection and Handling

For the samples follow appropriate techniques for handling specimens as per established guidelines (2,3). After use, contaminated materials must be sterilized by autoclaving before discarding.

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 guidleines should be followed while handling specimens. Saftey guidelines may be referred in individual safety data sheets.

Limitations :

• 1. Some strains may show poor growth due to variable nutritional requirements.

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

Part A: Cream to yellow homogeneous free flowing powder Part B: Colourless viscous liquid

Colour and clarity of prepared medium

Yellow clear to slightly opalescent solution

Reaction

Reaction of the medium (1.8 w/v Part A + 4.0% w/v Part B) at 25°C. pH: 6.9±0.2

pH

6.70-7.10

Cultural Response

Cultural characteristics observed after an incubation at 35-37°C for 18-48 hours.

Key: (*) Corresponding WDCM numbers.

Storage and Shelf Life

Store between 10-30°C in a tightly closed container and the prepared medium at 15-25°C. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle inorder 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. Faverco [chem.], 1967, Microbiological Sampling of Surfaces, Biological Contamination Control Committee, American Assoc. for Contamination Control
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.