Growth Promotion Test of Media

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Growth Promotion Test of Media

1.0 Objective
To lay down a procedure for Growth Promotion Test of Media.
2.0 Scope
This Standard Operating Procedure is applicable at Microbiology Laboratory, Quality Control Department of abc company.
3.0 Responsibility
3.1 Concerned Officer/Executive shall be responsible to follow this SOP.
3.2 Department Head or his designee shall be responsible to implement and ensuring to compliance of this SOP.
4.0 Abbreviations and Definitions
QC : Quality Control
GPT : Growth Promotion Test
LAF : Laminar Air Flow
GF : Growth promotion test Fails
GP : Growth promotion test Pass
SOP : Standard Operating Procedure
5.0 Procedure
5.1 GPT of received dehydrated media:
5.1.1 GPT shall be performed of all the new lots of dehydrated media received by selecting the randomly one

box of dehydrated media. If at any point the same lot of the same dehydrated media is received then GPT shall not be performed again.
5.1.2 Clean the LAF and carry out the testing under the LAF unit.
5.1.3 The inoculum shall be prepared as per the SOP No.
5.1.4 Test for Growth Promoting Properties, Liquid Media: Inoculate a portion of the appropriate medium

with a small number (not more than 100 cfu) of the appropriate microorganism as per the Annexure-2.

Incubate at specified temperature for not more than the shortest period of time specified in the test. Clearly

visible growth of the microorganism comparable to that previously obtained with a previously tested and

approved batch of medium occurs.
5.1.5 Test for Growth Promoting Properties, Solid Media: Perform Pour plate /Spread Method, inoculating each

plate with a small number (not more than 100 cfu) of the appropriate microorganism as per the Annexure-2.

Incubate at specified temperature for not more than the shortest period of time specified in the Annexure-2.

Clearly visible growth of the microorganism comparable to that previously obtained with a previously tested

and approved batch of medium occurs.
5.1.6 Test for Inhibitory Properties, Liquid or Solid Media: Inoculate a portion of the appropriate medium with

at least 100 cfu of the appropriate microorganism as per the Annexure-2. Incubate at specified temperature for

not less than the longest period of time specified in the Annexure-2. No growth of the microorganism occurs.
5.1.7 Test for Indicative Properties: Perform Pour plate / Spread Method, inoculating each plate with

a small number (not more than 100 cfu) of the appropriate microorganism as per the Annexure-2.

Incubate at specified temperature for a period of time within the range specified in the Annexure-2.

Colonies are comparable in appearance and indication reactions to those previously obtained

with a previously tested and approved batch of medium.
5.1.8 During release of lot / batch of autoclave media and each lot / batch of ready to use media, for solid media,

the number of organisms added and the number of organisms recovered need to be determined. A count

of any of the test organisms differing by factor of 2 of the calculated value of the inoculum shall be obtained.
5.1.9 Observation for every load of autoclaved media prepared shall be recorded in the growth promotion test

and pre-incubation check record.
5.1.10 For new packs of dehydrated medium: If the medium does not support the growth of microorganisms return

all the packs of the lot to the manufacturer.
5.1.11 If any load of medium prepared for testing purposes does not support the growth of appropriate microorganisms,

then that load of the medium shall be discarded and test results are deemed invalid.
5.1.12 When a batch of media does not meet the requirements of growth promotion testing, an investigation shall be

initiated to identify the cause. This investigation shall include a corrective action plan to prevent the recurrence of

the problem. Any non conforming lot shall not be used if an assignable cause or corrective resolution relative to

non growth support is undetermined.
5.1.13 The list of media with test microorganisms for growth promotion, inhibition and indicative properties and

incubation condition for GPT is listed in Annexure-2.
5.1.14 Record the results of GPT in the GPT register as per Annexure-1.
5.1.15 If GPT passes, put √ over label as GPT Pass and media can be use for further use and if GPT fails

put √ over GPT Fail and media must not be used.

5.1.16 A GPT reference number such as WWWW/XXX/YY/ZZ shall be assigned to each media passing or

failing the test, where WWWW is the short form of an individual media (could vary from two digits to four digits),

XXX is a three digit serial number as 001, YY is the year of testing as 11 for 2011 and ZZ would signify GPT pass as

GP or GPT fail as GF.
5.2 GPT of routine media preparation for microbiological testing:
5.2.1 GPT shall be performed on each prepared lot of media for microbiological testing.
5.2.2 Clean the LAF and carry out the testing under the LAF unit.
5.2.3 The inoculum shall be prepared as per the SOP No.
5.2.4 Test for Growth Promoting Properties, Liquid Media: Inoculate a portion of the appropriate medium

with a small number (not more than 100 cfu) of the appropriate microorganism as per the Annexure-2.

Incubate at specified temperature for not more than the shortest period of time specified in the test.

Clearly visible growth of the microorganism comparable to that previously obtained with a previously tested

and approved batch of medium occurs.
5.2.5 Test for Growth Promoting Properties, Solid Media: Perform Pour plate / Spread Method,

inoculating each plate with a small number (not more than 100 cfu) of the appropriate microorganism as

per the Annexure-2. Incubate at specified temperature for not more than the shortest period of time specified

in the Annexure-2. Clearly visible growth of the microorganism comparable to that previously obtained with

a previously tested and approved batch of medium occurs.
5.2.6 Test for Inhibitory Properties, Liquid or Solid Media: Inoculate a portion of the appropriate medium with

at least 100 cfu of the appropriate microorganism as per the Annexure-2. Incubate at specified temperature for

not less than the longest period of time specified in the Annexure-2. No growth of the microorganism occurs.
5.2.7 Test for Indicative Properties: Perform Pour plate / Spread Method, inoculating each plate with a small

number (not more than 100 cfu) of the appropriate microorganism as per the Annexure-2. Incubate at specified

temperature for a period of time within the range specified in the Annexure-2. Colonies are comparable in

appearance and indication reactions to those previously obtained with a previously tested and approved

batch of medium.
5.2.8 During release of lot / batch of autoclave media and each lot / batch of ready to use media, for solid media,

the number of organisms added and the number of organisms recovered need to be determined.

A count of any of the test organisms differing by factor of 2 of the calculated value of the inoculum shall be obtained.
5.2.9 Observation for every load of autoclaved media prepared shall be recorded in the growth promotion test

and pre-incubation check record.
5.2.10 For new packs of dehydrated medium: If the medium does not support the growth of microorganisms

return all the packs of the lot to the manufacturer.
5.2.11 If any load of medium prepared for testing purposes does not support the growth of appropriate

microorganisms, then that load of the medium shall be discarded and test results are deemed invalid.
5.2.12 When a batch of media does not meet the requirements of growth promotion testing, an investigation

shall be initiated to identify the cause. This investigation shall include a corrective action plan to prevent

the recurrence of the problem. Any non conforming lot shall not be used if an assignable cause or corrective

resolution relative to non growth support is undetermined.
5.2.13 The list of media with test microorganisms for growth promotion, inhibition and indicative properties

and incubation condition for GPT is listed in Annexure-2.
5.2.14 Record the results of GPT in the GPT register as per Annexure-1.
5.2.15 A GPT reference number such as WWWW/XXX/YY/ZZ shall be assigned to each media passing or

failing the test, where WWWW is the short form of an individual media (could vary from two digits to four digits),

XXX is a three digit serial number as 001, YY is the year of testing as 11 for 2011 and ZZ.
6.0 Forms and Records
6.1 Record for Growth Promotion Test – Annexure-1
6.2 List of media with test microorganisms for growth promoting, inhibitory and indicative properties – Annexure-2
7.0 Distribution
7.1 Master copy – Documentation Cell (Quality Assurance)
7.2 Control copy – Quality Control

8.0 History