Media Preparation for Microbiological Analysis

Standard Operating Procedure (SOP) for Microbiological Media Preparation. Media are required for cultivating the Micro-Organism. Microbiology Media should be prepared in proper way with adjusting proper pH required for growth of Micro-Organism.

Preparation of Microbiology Media

1.0   Objective :

• • To lay down a procedure for preparation of media for microbiological tests.

2.0   Scope :

• • This SOP is for preparation of media in Microbiology Laboratory.

3.0  Procedure for Media Preparation:

• • Microbiology Media are required for cultivating the Micro-Organism.

• • The Media should be prepared in proper way with adjusting proper pH required for growth of Micro-Organism.

• • Media are of 2 types:

• • • Solid Media (Agar)

• • • Liquid Media (Broth)

• • Method of Preparation of Media:

• • Medium for Microbiological testing should be prepared as per requirement.

• • The amount of medium to be prepared is depend upon the samples i.e.

• • • Raw Materials,

• • • Water,

• • • Finished products,

• • • Stability,

• • • Drain and

• • • Environment monitoring etc.

• • To be tested Microbiologically so that media should not get wasted.

• • Do not prepare excess amount of media during media preparation because it is very sensitive and can get contaminated or spoiled during the course of time.

• • For preparing any culture media (Solid or Liquid) take properly cleaned glass apparatus i.e. conical flasks, Bottles, tubes etc. of different volumes as per requirement.

• • Follow the instructions given by the manufacturer of media for preparing the culture media.

• • Weigh the required quantity of media mentioned on the label of the container and reconstitute with purified water and mention media details (Date, Media name) on tubes, flasks, bottles and enter the detail in media preparation record (Annexure-I) and media consumption record (Annexure-II).

• • Heat the media on hot plate to dissolve it completely.

• • Cool to room temperature then adjust the pH (by using either 0.1M HCL or 0.1M NaOH) specified on the label and plug the flask with non absorbent cotton, cover with aluminum foil.

• • Sterilize or boil to heat the media as per instruction given on the pack by the manufacturer.

• • The lot no. of media shall be given as AM-XX/001 (for Autoclable media) and BM-XX/001(For Boiled media). Where XX stand for last two digit of the current year.

• • For agar media, cool the media to about 40-45°C then Pour the sterilized media under LAF into the sterilized Petri dish or test tube as per requirement

• • Use the plate master for spreading of media in to Petri dish.

Related : Preservative Efficacy Test Procedure

• • Cool the prepared media to 25ºC at room temperature for solidification.

• • After solidification of media check the pH of the solid and agar media.

• • Place the prepared media plates or test tubes in Incubator at 30-35°C for 18-24 hours for pre incubation.

• • Used media details shall be entered in Annexure-III (Media Plate/ Tubes Consumption Record)

• • Before Use check the media for any growth, if any growth is observed information shall be given to Head QA & Head QC in case any deviation observed.

• • Testing of Media:

• • pH: From each quantity of nutrient media, which is prepared in one run , take a sample after autoclaving and let it cool down to room temperature.

• • Measure the pH value of the media. Media pH should be between 0.2 from the initial pH.

• • If pH not meets the acceptance limit, the media must not be used and is to be discarded.

• • Pre incubation:

• • Before pre incubation of culture media, Label the media name and lot no. on plates, tubes, flasks which are already given in annexure-III and then incubate the media for 18-24 hrs in incubator.

• • After pre incubation of media, store the media on room temperature and visually inspect the media for any contamination.

• • If there is any contamination then discard the media as per SOP.

4.0   Reference (S)

• • Indian Pharmacopoeia & Manufacturer specification.

• • USP chapter No. 62

5.0   Annexure (S)

Annexure I : Media Preparation Record

Instrument       :  Analytical Balance                                                 Month / Year: …………….

Make                :  …………….                                                                  Eq. No.: …………….

Model               :  …………….                                                                 Ref. SOP. No. : …………….

Annexure II : Media Consumption Record

Name Of Media: ………………..….……………                                Lot No.: ……………………………..……….

Mfg. Date of Media……………….……………..                               Expiry Date of Media: ……………………..

Date of Opening: ……………………………….                                GPT Status: …………………….……………

Annexure III : Media Plate/ Tubes Consumption Record

Name of Media: …………………………………….….                          Media Lot No.: ………………..…..…………

Date of preparation of media: ……………………….                         Valid up to: ………………….……………….

Total No. of Plates/ Tubes/ flasks: ………………….

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