Micro Biological Testing


Microbiology testing is critical for ensuring that your different product type meets the required microbiological limits and determining the Antimicrobial Effectiveness Test (AET), Microbial limit test, as well as identifying microorganisms and contamination. Our dedicated microbiology laboratory is on standby to provide qualitative and quantitative assessments of non-sterile products using USP, FDA/BAM, and in-house methods. With over 40 years of experience in this field, we help our clients determine the tests that best fit their needs and support their products’ compliance with relevant regulatory requirements or support on research products microbiologically.

Microbiology: Testing Methods

<61><62> Suitability Testing
<60> Burkholderia cepacia
<2021><2022> Nutritional and Dietary Supplements Testing and absence of a specified organisms.
<51> Antimicrobial Effectiveness Testing
<62> Microbial Enumeration Testiong
- Total Aerobic Microbial Count
- Total Yeasts and Molds Count
<62> Bile Tolerant Gram Negative Bacteria
<62> Escherichia coli (E.coli)
<62> Salmonella
<62> Pseudomonas aeruginosa
<62> Staphylococcus aureus
<62> Clostridia
<62> Candida albicans
<85> Endotoxins
<2021> Heterotrophic Plate Count on Process Water
<2021> Total Yeasts and Molds Count
<2021> Bile Tolerant Gram Negative Bacteria
<2022> Escherichia coli (E.coli)
<2022> Salmonella
<2022> Pseudomonas aeruginosa
<2022> Staphylococcus aureus
<2022> Clostridia

Method Qualification & Release Testing

What is method qualification, and why is it significant? Method Qualification is an integral part of any microbiological test system. It allows us to determine the appropriate diluent/dilution factors/enrichment media required to neutralize any inherent antimicrobial properties of drug products and ingredients (tested according to USP chapters <51>, <61> and <62>) when sample preparations are challenged with specific, viable test microorganisms.

Microbial Enumeration Tests - USP <61> Counting Method
Counting Method (Total Aerobic & Total Combined Yeast/Mold Counts)
Tests for Specified Microorganisms - USP <62> Test Method
Bi le Tolerant Gram-Negative Bacteria, Presence/Absence (Qualitative)
Bile Tolerant Gram-Negative Bacteria, Most Probable Number (Quantitative)
* B.cepacia USP<60> Presence/Absence 
E.coli Presence/Absence 
Pseudomonas aeruginosa Presence/Absence 
Salmonella species Presence/Absence 
Staphylococcus aureus Presence/Absence 
Candida albicans Presence/Absence 
Clostridium species Presence/Absence 

When and how often is this test administered?

Suitability testing is performed on a new product or change formulation or new testing site. Some of our clients request that we run several tests concurrently, including suitability testing, but we recommend that suitability testing be performed before any other tests. Should suitability testing fail for your product, then the results of any concurrent tests would be invalidated and unusable. it is required for regulatory submission for FDA approval for all products. CGMP regulations, which are enforced by the FDA, require that methods are suitable for a given product. The FDA will require evidence that the tests given are valid for a given product with a recorded demonstration of validity.

Facility Monitoring and Support

  • Chromak Research offers a comprehensive range of microbiology and chemistry capabilities in support of your facility monitoring and process validation projects—all performed in strict adherence to cGMP requirements.
  • We offer outstanding service and flexible options in sample collection with daily sample courier service in the U.S. and pickup and analysis of samples on weekends (with advance arrangements by the client).
  • We can provide sample collection containers for your Process Water Testing and Environmental Monitoring.
Process Water Testing (EP/USP/JP/BP)
On-Site Sample Collection
Coliform Bacteria (presence/absence)-Qualitative
Coliform Bacteria Count (quantitative)
Total Aerobic Microbial Count (membrane filtration or pour plate)
Endotoxin Testing (By Gelclot Method)
Conductivity, USP <645>
Total Organic Carbon (TOC), USP<643>
Heterotrophic Plate Count
Heavy Metals Testing
Environmental Monitoring
On-Site Sample Collection
Total airborne non-viable particulate count by Met one machine.
Total Aerobic Plate Count, Viable Air Sampler or Settling Plates
Total Combined Yeast / Mold Count, Viable Air Sampler or Settling Plates
Total Aerobic Plate Count, Compressed Air Sample
Cleaning Validation
Total Aerobic Plate Count, Contact (RODAC)Plates
Total Aerobic Plate Count, Swab Samples
Total Combined Yeast/ Mold Count, Contact (RODAC) Plates
Total Combined Yeast/ Mold Count, Swab Samples
Total Organic Carbon (TOC), Swab Samples, USP <643>
Organism Identification of Isolates
Gram stain only
Coagulase Test
Oxidase Test
AccuPro-ID® (environmental monitoring & water samples)
AccuGENX-ID® (raw materials & product samples)
1. AccuPro-ID® and AccuGENX-ID® are performed by subcontract Laboratories