Phosphate - Buffered Saline (PBS), pH 7.4

Intended use

Phosphate-Buffered Saline (PBS), pH 7.4 is used for the preparation of dilution, blanks for the examination of samples from food, water and other clinical and non-clinical specimens.

Composition**

Final pH ( at 25°C): 7.40

**Formula adjusted, standardized to suit performance parameters

Directions

Suspend 8.58 grams in 1000 ml purified /distilled water. Dispense in test tubes or flasks as desired. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.

Principle And Interpretation

Phosphate Buffered Saline (PBS) pH 7.4 is prepared as recommended by BAM (2). It is used as a diluent and sample preparation of Vibrio species. Phosphates maintain the pH of the medium and sodium chloride maintains the osmotic balance.

Type of specimen

Clinical samples - Stool samples; Food and dairy samples; Water samples

Specimen Collection and Handling

For clinical samples follow appropriate techniques for handling specimens as per established guidelines (3,4).

For food and dairy samples, follow appropriate techniques for sample collection and processing as per guidelines (2).

For water samples, follow appropriate techniques for sample collection, processing as per guidelines and local standards.(1)

After use, contaminated materials must be sterilized by autoclaving before discarding.

Warning and Precautions

In Vitro diagnostic use. 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 clinical specimens. Safety guidelines may be referred in individual safety data sheets.

Limitations

NA

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: White to cream homogeneous free flowing powder

Colour and Clarity of prepared medium: Colourless clear solution without any precipitate

Reaction: Reaction of 0.86 % w/v aqueous solution at 25°C. pH : 7.40

pH: 7.40

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 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 (3,4).

Reference

1. Baird R.B., Eaton A.D., and Rice E.W., (Eds.), 2015, Standard Methods for the Examination of Water and Wastewater, 23rd ed., APHA, Washington, D.C.
2. E.L.Elliot,C.A.Kaysner,L.Jackson,M.L.Tamplin, V.cholerae, V.parahaemolyticus, V.vulnificus and other Vibrio spp. Bacteriological Analytical Manual, 8th Edition, 1995.
3. Isenberg, H.D. Clinical Microbiology Procedures Handbook 2nd Edition.
4. 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.