Preparation and sterilization of medias

 

1.     Purpose:-                         

          To describe the procedure for the preparation and sterilization of different Medias used in

 Microbiological testing.

2.     Scope:-

          This procedure is applicable for preparation & sterilization of Medias.

3.     HSE Statement:-

           Face mask and gloves should be used.

4.     Responsibilities:-

                               i)      Manager Quality Control is responsible to ensure that procedure & formats are followed entirely as approved.

                             ii)      Microbiologist is responsible to perform the test.

                           iii)      Lab attendant is responsible to assist the officer microbiologist for the preparation of test materials.

5.     Materials:-

   5.1 Type of media to be prepared in dehydrated form.

         5.2 Fresh hot distilled water.

5.3 Washed media bottles.

5.4 Weighing balance, which supports the required weight for weighing.

5.5 Hot plate with stirrer.

5.6 Butter paper and spatula                          

5.7 pH meter

6.0 Definitions:

  6.1 Media:

 Media is the nutritive source for the cultivation of microorganisms. The media usually prepare from protein by acid or enzymatic digestion. Medias are usually available in dehydrated form. We have only to mix required measured quantity in distilled water. Follow instructions for preparation as mentioned on the label of media container.

  6.2 Sterilization:

                It is the process of killing or removing microorganisms. Media is sterilized by autoclaving at  

                121⁰C for 15 minutes at a pressure of 15 PSI.

7.0 Flow Chart:-

 

8.0 Description:-

     

      8.1 Procedure:-

     8.1.1 Check the physical state and expiry date of the media.

     8.1.2 Weigh accurately required amount quantity of dehydrated media as per manufacturers

Instructions on the label in a media bottle.

8.1.3   Mix the weighed amount of dehydrated media in equal quantity of hot distilled water as per mentioned on the label.

8.1.4   Dissolve by continuous heating and stirring on hot plate until solution becomes completelyclear.

8.1.5 Check the pH of media before and after sterilization according to their specifications.

8.1.6   If media for sterility test is being prepared, dispense equal amount of 100ml in separate media flasks and mention the type of media on the flak.

8.1.7   Screw up the corks of media bottles keeping them a little bit loose in order to avoid the breakage of      media bottle during sterilization cycle.

8.1.8   Sterilize all Medias for which supplier’s recommendations are available at 121 C for 15 minutes.

8.1.9   Use AUTOCLAVE STERILIZATION INDICATOR TAPE with each load that indicates proper

sterilization.

     8.1.10 Immediately tight the screw caps of all media containers after sterilization. period and allot Lab

numbers for back traceability.

    8.1.11 Incubate all Medias at their respective optimum growth temperatures.

    8.1.12   Pre incubations of all prepared Medias are necessary for a period of 3-5 days.

    8.2 Growth Promotion Test of Medias (Positive Control):

     Growth promotion test of each lot of media prepared should be performed as per SOP.

   9. Forms and Records:-

     9.1 Sterilization and Preincubation record of Medias

     9.2 Log of Sterilization Cycle

     9.3 Growth Promotion test

10. References:  USP 35

  11 Distributions:-

This SOP has to be distributed in below mentioned Departments:-

Sr. NO	Distributed to	Received (Current)	Returned (Obsolete)
1	Quality Control Department
2	Quality Management Department

12. Revision History:-

         

N/A