1 Scope
This standard specifies quality requirements for medium and reagents for food microbiological examination. This standard is applicable to quality control of medium and reagent for food microbiological examination.
2 Terms and Definitions
2.1 Quality control
Technical operation and activities carried out for the purpose of quality requirements.
2.2 Batch of medium or reagent
Complete traceable unit of medium or reagent, it may be a certain amount of semi-finished products or finished products which conform to the product requirements (internal control) and performance test and have stable product model and quality. The products are produced in a certain production cycle and have the same number.
2.3 Performance of medium and reagent
Reaction of the medium to testing bacterial strain under specified conditions.
2.4 Medium
Liquid, semisolid or solid subtances, containing natural or synthetic components, used to ensure the microorganism breeding, no matter whether the microorganism bacteriostat is available, appraise or keep its vitality.
2.5 Chemically defined medium
A medium prepared by chemical components with known molecular structure and purity.
2.6 Undefined and partially-defined chemical medium
A medium, wholly or partially composed of natural substances, processed subtances or other impure chemical substances.
2.7 Solid medium
A medium that is solidified and becomes solid, when a certain amount of condensate (agar and gelatine for example) is added into the liquid medium and heated until 100℃ before dissolving and cooling.
"Plate" is the solid medium in the plate; "slant" is the solid medium solidified after being put into the test tube and placed in an inclined form.
2.8 Semisolid medium
A semisolid medium formed when a certain amount of condensate (agar and gelatine for example) is added into the liquid medium and heated until 100℃ and then dissolved and cooled.
2.9 Transport medium
A medium that protects and maintains the microorganism activities and prevents the obvious proliferation within a period between sampling and laboratory treatment. The transport medium shall not contain substances making the microorganism proliferate, but the medium shall be able to protect the bacterial strain (e.g. Buffered Glycerol- Sodium Chloride Solution transport medium).
2.10 Preservation medium
A medium that protects and maintains the microorganism activities within a certain period and prevents the adverse effect of long-time preservation or makes the activities recovered easily after long-time preservation, such as nutrient agar slant.
2.11 Suspension medium
The microorganisms under test are dispersed to liquid phase and no proliferation or inhibition happen throughout the contact process (e.g. phosphate buffer solution).
2.12 Resuscitation medium
A medium that enables the impaired or stressed microorganism to be recovered and the microorganism to return to normal growth capability but not necessarily to promote microorganism reproduction.
2.13 Enrichment medium
Foreword I
1 Scope
2 Terms and Definitions
3 Quality Assurance of Medium and Reagent
4 Preservation and Use of Quality-control Strains
5 Quality Requirements for Medium and Reagents
6 Performance testing methods
7 Record of Testing Result
Appendix A Quality Problems Due to Incorrect Preparation of the Medium and Causes Analysis
Appendix B Preparation of Standard Storage Strain and Working Strain
Appendix C Compositions of Medium Specified in Microbe Inspection Standard for Food Safety
Appendix D Quality Control Criteria for Media and Reagents Made by Manufacturer and in Laboratory
Appendix E Quality Control Criteria for Commercial Medium and Reagent Used in Laboratory
Appendix F Spiral Plate Method
Appendix G Records for Test Results for Laboratory Media or Commercial Media
