Coliform testing
Coliform bacteria are indicator
organisms used to assess sanitary quality and potential contamination in raw
materials and finished products.
Tests We Offer
- Coliform Test — USP <61>/<2021>
Test Methodology
USP <61> Methodology (Microbial Enumeration Tests)
Under USP <61>, coliform testing is performed using a selective culture-based enumeration approach designed to recover and quantify indicator organisms.
- Sample is prepared and homogenized to ensure representative distribution
- Serial dilution is performed where required
- Inoculation onto selective and differential agar media
- Incubation under controlled temperature conditions
- Detection of lactose-fermenting colonies based on characteristic color change or gas production
- Enumeration of colonies to estimate microbial load
This method is primarily used for quantitative microbial limit testing (MLT) and supports compliance with pharmacopeial acceptance criteria.
USP <2021> Methodology (Microbial Examination of Non-Sterile Products)
Under USP <2021>, coliform testing is performed as part of a broader microbial examination framework for non-sterile products, with enhanced focus on recovery and confirmation of indicator organisms.
- Sample preparation with emphasis on neutralization of preservatives or inhibitory substances
- Use of selective enrichment media to promote recovery of stressed organisms
- Incubation under defined conditions to encourage growth of coliform bacteria
- Isolation on selective/differential media for Gram-negative lactose fermenters
- Confirmatory biochemical testing (e.g., oxidase-negative confirmation and lactose fermentation profile)
- Optional confirmatory identification for regulatory reporting
This approach is designed to ensure higher recovery accuracy in complex pharmaceutical and dietary supplement matrices.
Why it Matters
- Ensures sanitary quality of raw materials and finished products
- Detects contamination from water, handling, or processing failures
- Supports compliance with USP <61> and USP <2021> requirements
- Strengthens GMP and quality assurance programs
- Provides reliable microbial quality indicators for regulatory audits
How to Connect
Reach out to Unicorn Analytical
Services for coliform detection and testing.