Microbial Limit Test for Finished Products – SOP

5.1  Test Preparation:

• Suspend 10 gm of the Tablet/Capsule sample under examination in 90 ml sterile SCDM broth, mix well and  keep in incubator for incubation at 30°C to 35°C for 18 to 24 hrs.

5.2 FOR TOTAL AEROBIC MICROBIAL COUNT (TAMC):

• Take 1.0 ml of test preparation in sterile petri plate before incubation and pour the 15 to 20 ml of SCDA .
• Allow the plate to solidify at room temperature and keep in incubator for incubation at 30°C to 35°C for 5 days.
• Observe the plate after completion of incubation period and count the total number of colonies in cfu/gm.

5.3 FOR TOTAL YEAST AND MOULD COUNT (TYMC) :

• Take 1.0 ml of test preparation in sterile petri plate before incubation and pour the 15 to 20 ml of SCA .
• Allow the plate to solidify at room temperature and keep in incubator for incubation at 20°C to 25°C for 5 days.
• Observe the plate after completion of incubation period and count the total number of  colonies in cfu/gm.

5.4 TESTS FOR SPECIFIED PATHOGENS :

• Test for Escherichia coli:
  • After incubation, shake the test preparation and transfer 0.1 ml to 10 ml of Macconkeys broth, and incubate at 42°C to 44°C for 24 to 48 hr.
  • Take a loopful sample in Macconkeys broth and strick on Macconkeys agar plate and incubate at 30°C to 35°C for 24 hr.
  • Growth of pink, non mucoid colonies, indicates the presences of Escherichia coli.
  • If there is no growth of such type of colonies, or the identification tests  are negative, it indicates absence of E. coli and the product  passes  the test.
• Test for Salmonella aboney:
  • After incubation, shake the test preparation and transfer 0.1 ml to 10 ml of RVSE broth and incubate at 30°C to 35°C for 24 to 48 hr.
  • Take a loopful sample in RVSE broth and strick on XLDA plate and incubate at 30°C to 35°C for 24 hr.
  • Well developed, red colonies with or without black centers indicates the presences of Salmonella aboney.
  • If there is no growth of such type of colonies, or the identification tests are negative it indicates absence of Salmonella aboney and the sample passes the test.
• Test for Pseudomonas aeruginosa :
  • After incubation of test preparation, take a loopful of suspension and strick on Cetrimide agar plate and incubate at 30°C to 35°C for 18 to 72 hours.
  • A greenish colony indicates the possibility of presences of Pseudomonas aeruginosa.
  • If there is no growth of such type of colonies, or the identification tests are negative it indicates absence of Pseudomonas aeruginosa and the sample passes the test.
• Test for Staphylococcus aureus:
• After incubation of test preparation, take a loopful of suspension and strick on Mannitol salt agar plate and incubate at 30°C to 35°C for 18 to 72 hours.
• Yellow or white colonies with yellow zone indicates the possibility of presences of Staphylococcus aureus.
• If there is no growth of such type of colonies, or the identification tests are negative it indicates absence of Staphylococcus aureus and the sample passes the test.

5.5 LIMITS :

• As per individual material specifications.