5.1 |
Safety Precautions: |
5.1.1 |
Always wear protective masks and gloves while performing micro activities. |
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5.1.2 |
Use clean Spatula, cleaned and dried with 70% v/v Isopropyl Alcohol for weighing of each media. |
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5.2 |
Procedure of Shelf Life Determination : |
5.2.1 |
Refer Procedure for Media Preparation and Sterilisation SOP for preparation of reconstituted media. |
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5.2.2 |
For the List of Media to be prepared and individual procedure refer respective SOP for preparation of reconstituted media. |
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5.2.3 |
Enter all dehydrated media weighed and update the stock in annexure. |
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5.2.4 |
Enter the Details for the weighing, dispensing, pH and autoclaving of Media in annexure. |
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5.2.5 |
Prepared liquid media shall be distributed aseptically in a suitable capacity previously sterilized conical flasks/ bottles/Test tubes. |
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5.2.6 |
Affix label containing name of the media, batch number, date of preparation and signature. |
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5.2.7 |
Sufficient Media Should be prepared considering the amount required to perform all the tests for all the days of the study. Number of organisms for the Growth promotion test has to be calculated before Media preparation. |
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5.2.8 |
Eg. If SCDM is to be prepared for study then consider the number of Organisms for GPT i.e. 7 organisms + Media control= 8 x 10 ml + pH= 1 x 10 ml + Other test together (discolouration, sedimentation, precipitation and contamination) = 1 x 10 ml: Total = 100 ml per day of study.
This step has to be repeated for 8 days of the study, accordingly minimum of 800 ml SCDM media has to be prepared for the study. |
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5.2.9 |
Store the media in an incubator at 20-25°C or in the refrigerator at 2-8° C.
Ensure that the media should be at room temperature after removing from the refrigerator and before performing the study. |
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5.3 |
Different Time Intervals Check for Growth Promotion study and physical observation. |
5.3.1 |
The growth promotion capability to be determine at following intervals. Initial, 1st day, 3rd day, 7th day, 14th day, 21st day, 28th day and 31th day. |
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5.3.2 |
While ascertaining the shelf life of media, following observations are to be recorded in the Annexure. |
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5.3.3 |
At each stage, prepared Media are checked for physical observation such as discolouration, sedimentation, precipitation and contamination. Record the parameters in Annexure. and observe its validity at each stage. |
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5.3.4 |
At any given time within the study days, pH should not vary from given range for individual reconstituted media. |
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5.3.5 |
Growth promotion test should comply when tested initially and during the particular storage period. Refer SOP “Procedure for Growth promotion, Inhibitory and Indicative Properties of Culture Media.” |
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5.3.6 |
For Culture Medium, incubation parameter and No. of organisms to be tested for growth promotion, Refer SOP “Procedure for Growth promotion, Inhibitory and Indicative Properties of Culture Media.”. |
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5.3.7 |
Enter results of each day in the Annexure for comparing and noting down the Results to determine the Shelf life. |
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5.3.8 |
If reconstituted media fails for any one of following tests: Physical appearance or pH or Growth promotion test, previous stage results which are complying will be considered as shelf life of that media. |
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5.3.9 |
Enter the Details in Equipment usage log books like Incubator, pH Meter, Autoclave, LAF etc. and other Documents like Media Consumption to be updated online to prevent any discrepancy in recording. |
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5.3.10 |
All the Used media and glasswares used for study, after completion of incubation and recording of results has to be Decontaminated in autoclave before disposal as per SOP -Destruction of Microbial waste. |
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5.4 |
Acceptance Criteria: |
5.4.1 |
The shelf life of each individual reconstituted media will be determined based on no major change in physical appearance, pH and growth promotion test values from the initial values upto the maximum duration of study. |
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5.4.2 |
Above steps are performed Initially once to validate shelf life of each media. |
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