Standard Operating Procedure for Microbial Identification Using Biochemical Testing in AMD
| Department | Analytical Method Development |
|---|---|
| SOP No. | SOP/AMD/222/2025 |
| Supersedes | SOP/AMD/222/2022 |
| Page No. | Page 1 of 12 |
| Issue Date | 21/05/2025 |
| Effective Date | 23/05/2025 |
| Review Date | 21/05/2026 |
1. Purpose
This SOP outlines the standardized procedure for identifying bacteria and fungi using biochemical testing techniques, including the use of commercial identification kits and confirmatory manual tests, for characterization of
microbial isolates from pharmaceutical environments or product samples.
2. Scope
This procedure applies to microbial isolates obtained during preservative efficacy testing, environmental monitoring, water testing, and product sterility assessments within the Analytical Method Development (AMD) department.
3. Responsibilities
- Microbiologist: Prepares inoculum, performs biochemical identification tests, and interprets results.
- Lab Assistant: Assists in media preparation, incubation, and maintenance of microbial stock cultures.
- Group Leader: Reviews and approves identification reports.
- QA Executive: Verifies adherence to procedures and ensures test results are documented in line with regulatory expectations.
4. Accountability
The Head of Analytical Method Development is accountable for ensuring accurate and validated identification of microbial contaminants or isolates using approved biochemical test procedures.
5. Procedure
5.1 Culture Preparation
- Revive microbial isolate on appropriate solid media (e.g., Nutrient Agar, Sabouraud Dextrose Agar).
- Incubate at 30–35°C for bacteria and 20–25°C for fungi for 24–72 hours as appropriate.
- Confirm purity of isolate by streaking on fresh media before identification.
5.2 Biochemical Identification
- Use commercial biochemical test kits (e.g., HiBac™, API™, or equivalent).
- For Gram-negative bacteria: Use enteric identification systems.
- For Gram-positive cocci: Use catalase, coagulase, and salt tolerance tests.
- For yeasts: Use sugar assimilation and urease tests.
- Follow manufacturer’s protocol for:
- Inoculum preparation (0.5 McFarland standard)
- Inoculation and incubation
- Reading color reactions or turbidity results
- Enter results into software or coding charts provided by the kit manufacturer.
5.3 Manual Confirmatory Tests (if required)
- Perform manual tests such as:
- Indole, Methyl Red, Voges-Proskauer, Citrate (IMViC)
- Triple Sugar Iron (TSI) slants
- Oxidase, Catalase, Urease tests
- Use positive and negative control organisms for each test.
- Record observations with interpretation in Annexure-1.
5.4 Data Recording and Interpretation
- Record biochemical profiles in the template provided (Annexure-2).
- Report identification up to genus and species level where possible.
- Document uncertainty in identification and recommend re-confirmation if required.
6. Abbreviations
- SOP: Standard Operating Procedure
- API™: Analytical Profile Index
- CFU: Colony Forming Units
- IMViC: Indole, Methyl Red, Voges-Proskauer, Citrate
7. Documents
- Manual Biochemical Test Result Log – Annexure-1
- Identification Result Report Template – Annexure-2
- Biochemical Kit Lot and Expiry Tracker – Annexure-3
8. References
- USP <62> Microbiological Examination of Nonsterile Products: Tests for Specified Microorganisms
- Indian Pharmacopoeia: Microbiological Tests
- Manufacturer protocols for HiMedia™, bioMérieux™, or equivalent kits
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | Meena Joshi | Deepak Goyal | Sunita Reddy |
| Designation | Microbiologist | QA Reviewer | Head – AMD |
| Department | Analytical Method Development | QA | Analytical Method Development |
11. Annexures
Annexure-1: Manual Biochemical Test Result Log
| Test | Result | Interpretation | Controls Used |
|---|---|---|---|
| Indole | Positive | Escherichia coli | E. coli (Positive), S. aureus (Negative) |
Annexure-2: Identification Result Report
| Sample ID | Biochemical Kit Used | Profile Code | Organism Identified | Confidence Level |
|---|---|---|---|---|
| ISO-23-001 | API 20E | 5144772 | Enterobacter cloacae | 99.5% |
Annexure-3: Kit Lot and Expiry Record
| Kit Name | Manufacturer | Lot No. | Expiry Date | Status |
|---|---|---|---|---|
| HiBac™ GN ID | HiMedia | HB2345 | 31/08/2025 | Active |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 21/05/2025 | 2.0 | Integrated biochemical test kits and added confirmatory test annexures | Annual Review and Audit Update | Sunita Reddy |
| 10/05/2022 | 1.0 | Initial SOP Release | New SOP | QA Head |