X

Growth Promotion Test (GPT) – Procedure

Standard Operating Procedure (SOP) for Growth Promotion Test (GPT) of Microbiological Media in Microbiology Laboratory.

Growth Promotion Test (GPT)

1.0   Objective :

    • To lay down a procedure for Growth Promotion Test (GPT) of culture media.

2.0   Scope :

    • This SOP is applicable to check the effectiveness of all dehydrated media purchased in Microbiology Laboratory.

3.0  Procedure – Growth Promotion Test (GPT) :

    • After receipt of dehydrated media check the media for expiry date and seal.
    • Enter the details along with container no. in the media reconciliation record and write the date of receiving on each container.
    • Write date of opening on the container.
    • Each New lot of media shall be qualified for Growth Promotion Test (GPT).
    • Preparation of Culture Suspension:

    • Prepare culture suspension containing 10-100 cfu.
    • Growth Promotion Test (GPT) for Agar Media (Plate Method):

    • Use Wash, clean and dry the required glassware used for microbial Growth Promotion Test (GPT).
    • Prepare & autoclave the required agar media for Growth Promotion Test (GPT).
    • Add culture suspension containing 10-100 cfu for each organism as specified in Table 01.

Also Read : SOP for Technology Transfer of Drug Product

    • Pour 15 – 20 ml of required agar media aseptically under LAF and mix properly by rotating the plate on plate master. Allow the plate to solidify.
    • After solidification incubate all the plates as per time and temperature specified in Table 01.
    • Label a blank media plate as negative control and incubate it at a temperature as specified in Table 01.
    • Observe the plate for growth and note down the result in Annexure-I.
    • Growth promoting test (GPT) for Liquid media / broths media (Tube Method):

    • Use Wash, clean and dry the required glassware used for microbial Growth Promotion Test.
    • Prepare & autoclave the required broth media for Growth Promotion Test (GPT).
    • Add culture suspension containing 10-100 cfu for each organism under test as specified in Table 01.
    • Incubate all the tubes as per time and temperature specified in Table 01.
    • Label a blank media tube as negative control and incubate as per time and temperature as specified in Table 01.
    • The media test is considered satisfactory, if growth/ turbidity appear in the promoting/indicative organism and no growth or turbidity appears in Inhibitory organism.
    • The negative control does not show any presence of microbial growth / turbidity.
    • Observe the tubes for growth and note down the result in Annexure-I.
    • In case of any OOS reported during Growth Promotion Test (GPT) analysis, either for liquid or solid media shall be investigated as per Out of Specification.
    • Shelf life and Storage of dehydrated culture media:

    • Dehydrated culture media should be examined carefully before use to ensure maintenance of physical integrity, colour and free flowing nature.
    • Once opened, all dehydrated culture media shall be used within one year from date of opening of culture media and all expired culture media shall be discarded.
    • Culture media shall be store at control room temperature.

Table 01

Media Used Microorganism to be used Property Incubation Temperature Incubation Period
Soyabean casein digest medium

 

 

S. aureus

Promoting

30-35°C

18-24 hrs

P. aeruginosa
B. Subtilis
Soyabean casein digest agar E. coli

Promoting

30-35°C

18-24 hrs

S. aureus
P. aeruginosa
Sabouraud dextrose broth C. albicans Promoting 20 – 25°C 3-5 days
A. brasielliensis
Sabouraud dextrose agar C. albicans Promoting 20 – 25°C 3-5 days
A. brasielliensis
EMB Agar E. coli Promoting 30-35°C 18-24 hrs

R2A Agar

E. coli

Promoting

30-35°C

18-24 hrs

S. aureus
P. aeruginosa
GN Broth Shigella boydii Promoting

30-35°C

18-24 hrs

S. aureus Inhibitory
MacConkey’s Broth E. coli Promoting

42-44°C

24-48 hrs

S. aureus Inhibitory
MacConkey’s Agar E. coli Promoting 30-35°C 18-24 hrs
Psedomonas Flouresen Agar P. aeruginosa Promoting 30-35°C 24-48 hrs
Psedomonas pyocyanin Agar P. aeruginosa Promoting 30-35°C 18-24 hrs
Triple Sugar iron Salmonella Spp. Promoting 30-35°C 24-48 hrs
Manitol Salt Agar S. aureus Promoting 30-35°C 24-48 hrs
E.coli Inhibitory
Violet Red Blue Glucose Agar E.coli Promoting +

Indicative

30-35°C

18-24 hrs

P. aeruginosa
B12 Culture Agar E. coli (Mutant) Promoting 30-35°C 18-24 hrs
Vogel–Johnson Agar Base S. aureus Promoting 30-35°C 24-48 hrs
B12 Assay Agar E. coli (Mutant) Promoting 30-35°C 18-24 hrs
Xylose-Lysine –deoxycholate agar Salmonella Spp. Promoting 30-35°C 24-48 hrs
E.coli Indicative
Enterobacteria Enrichment Broth Mossel E.coli Promoting

30-35°C

24-48 hrs

P. aeruginosa Promoting
S. aureus Inhibitory
Rappaport Vassiliadis Salmonella Enrichment Broth Salmonella Spp. Promoting 30-35oC

30-35°C

18-24 hrs

18-24 hrs

S. aureus Inhibitory
Cetrimide agar P. aeruginosa Promoting 30-35°C 24-48 hrs
E.coli Inhibitory
SS agar Shigella boydii Promoting 30-35°C 24-48 hrs

4.0   Reference (S) – Growth Promotion Test (GPT) :

    • USP 38, volume-1 chapter no. 62.

5.0   Annexure (S)

Annexure  – I  : Growth Promotion Test (GPT).

Medium Name: ……………                                                    Media Code No.: ……………

Batch No. / Lot No.: ……………                                            Incubation Temp.: ……………        

Use Before: ……………                                                         Incubation Period: ……………

Quantity Received: ……………                                             Date of receiving of Media:……………

Quantity Sampled: ……………                                             Dilution label of Used culture:………..

Container / Bottle No. used for test: ……………

Test Started on: ……………

Test Competed on: ……………

Method used: Plate Pour / Tube Method

Dilution of organism strain:  

Microorganism Used

Strain No. Plate 1/ Tube 1

Plate 2 / Tube 2

Negative Control: Growth / No Growth

Remark : The media is suitable / not suitable for further use in testing.

Microbiologist                           Checked By                                          Approved By

******************************************END******************************************

Janki Singh: Mrs. Janki Singh is the professional pharmaceuticals Blogger. She has already posted more than #1000 articles on varrious topics at different blogging plateforms. Contact : guideline.sop@gmail.com

View Comments (0)