SOP For Growth Promotion Test of culture medias used for microbiological testing's is described in this post which you can follow in the section of microbiological lab. 

Objective:

This procedure has been established for culture medias used in microbiological testing's.

Scope:

This procedure is applicable to microbiology lab.

Responsibility:

Microbiologist.                              

Accountability:

Quality Control Manager.             

Procedure:      

Growth promotion test must e performed for each lot of the prepared media.

It has two methods either perform the test at the time of receiving new lot of media or with each microbiological analysis perform positive control test i.e. 

(growth promotion test).

For performing growth promotion test prepare at least two plates for inoculation of microbial culture.

For bacterial culture, inoculate approximately 1ml containing 100 CFU of the microbe from the stock culture on to the plate and pour 20-25ml of the sterilized media over the culture and swirl the plate to mix the culture with media and set for solidifying and then incubate at a temperature of 32oC±2.5oC for 48hrs.

For fungal culture, inoculate approximately 1ml of the microbial culture from the stock culture on to the plate and pour 20-25ml of the sterilized media over the culture and swirl the plate to mix the culture with media and set for solidifying and then incubate at a temperature of 22oC±2.5oC for 3-5days.

Prepare one media plate to serve as a negative control.  

Set the media for incubation at a specific temperature and time and observe the growth pattern. If no scanty of delayed growth observed then repeat the test at least for two more time and observe the behavior of growth pattern if the growth pattern is copious and early in both the repetitive trials then the media complies with specifications otherwise reject the media.