Tryptone Soy Agar | DM225

Tryptone Soy Agar | DM225

A general purpose isolation medium not based on meat products.

Leifson1 produced several peptones from casein, and found that pancreatic digests gave a peptone equivalent to other peptones prepared from pure proteins. Brewer2 found from studies of various vegetable extracts that soy peptone was the most satisfactory. Combining the two peptones gives a medium supporting the growth of a wide variety of aerobic and anaerobic micro-organisms, with or without added blood, giving typical colonies and clear haemolytic reactions.

Technical Formula

Directions
1. Suspend 37g of powder in 1 litre or the contents of the sachet, with agitation, in the stated volume of distilled or deionised water.
2. Autoclave at 121ºC (15p.s.i.) for 15 minutes.
3. Thoroughly mix before pouring

In Use

"Blood Agar"
Cool to about 45-50ºC and add asceptically 5- 10% sterile defibrinated animal blood. Mix gently and pour.
"Chocolate Agar"
Add 5-10% sterile defibrinated animal blood to the medium at 75ºC, mix gently and maintain at this temperature for 10 minutes. Pour plates. Alternatively heated blood plates may be prepared by keeping blood plates at 55ºC for 1-2 hours.