BioLumix Validation Book for Dietary Supplements

According to cGMP all dietary supplement products should to be tested in accordance with the methods described in USP <2021> and <2022>. The required assays might include Total Aerobic Microbial Count, Total Combined Mold and Yeast, Bile-Tolerant-Gram-Negative bacteria, and objectionable organisms (absent in 10 grams of organism such as Salmonella, E. coli, and sometimes S. aureus). To do these tests companies either send product samples to contract laboratories for microbiological testing or test their samples internally.  Many outside laboratories utilize BAM and AOAC methods that were never validated against the USP methodology for Dietary Supplement products.

BioLumix Validation BookFDA’s GMP inspection program for dietary supplements has evolved since its debut a few years ago, with the agency increasingly strict in its interpretations of the regulation and requirements.  Validation of any new microbiological method is required prior to entering its use in the commercial arena. The validation assures equivalency of the new method to the reference method. This means that the new technique or device is giving us “real results” that are reproducible and that can be trusted. USP <1223> Validation of alternative microbiological methods and ISO 16140 defines the general principle and the technical protocol for the validation of alternative methods in the field of microbiological analysis.

BioLumix generates a customized validation book for each of its customers. The book includes:

Installation qualification (IQ):  Identification and validation of the system components; validation of the environmental conditions; electrical requirements; computer qualification; verifying that all installation steps were followed;  and documentation of instrument calibration.

Operational qualification (OQ):  Verifying that the equipment is properly installed, calibrated and is operational.  It includes a unique SOP for all products and assay combinations to be performed on the instrument; software characteristics and the verification that the software is 21 CFR part 11 compliant; verification that all the instrument functions operate as expected; Verification of the instrument temperature accuracy; and training records.

Performance Qualification (PQ):

Performance qualification is the most extensive part of the BioLumix validation book. It shows equivalency with USP methodology when following USP <1223> “Validation of alternative microbiological methods”.

  • Side-by-side comparison: Side-by-side results are comparable between the BioLumix method and the reference method when testing by the BioLumix Dilute-to-Specification Protocol.   A generic study was performed testing all types of Nutraceutical, botanicals and dietary supplements for Total aerobic count. A total of 252 samples with counts in the range of 100 cfu/g to 10,000,000 cfu/g   were analyzed, including   botanical powders, botanical extracts, infusions, alcohol extracts, raw materials, and finished products. There was a 99.6% agreement between the BioLumix method and the SP plate count method. Testing similar products for yeast and mold counts in the range of 10 cfu/g to 100,000 cfu/g there was a 98.1% agreement; and for Gram negative Bile Tolerant bacteria 98.7% agreement.  Similar results are shown for all objectionable groups of organisms such as E. coli, S. aureus, P. aeruginosa, and Salmonella.  Unique customer samples are also tested and compared to USP results.
  • Specificity (Inclusivity and Exclusivity): is the ability of the media in each vial to detect a wide range of organisms belonging to the target group, and not detect using non-target organisms, which demonstrates that the method is fit for its intended purpose.  The inclusivity and exclusivity of each of the media used by the system was extensively studied.  The data shows good inclusivity and exclusivity.
  • Limit of detection (LOD):  are the lowest microbial counts in a sample that can be detected under the conditions used.  The limit of detection was evaluated for Total Aerobic count, Yeast and Mold count and Gram negative Bile Tolerant bacteria.  The data shows that for all 3 media the limit of detection was close to 1-3 cfu/vial.
  • Precision and Repeatability:  is the degree of agreement among individual test results when repeatedly testing multiple samples of suspensions of microorganisms across the range of the test.  It is usually expressed as standard deviation (SD) or coefficient of variation (CV) of a series of measurements. Generally, a %CV of 15%-35% is acceptable. All the results obtained were well within the acceptable range.
  • Robustness: indicates the capacity of the device or technique to absorb small variations such as: incubation conditions, incubation temperature, media and sample volumes, etc.   The data demonstrates the robustness of the system with various media.
  • Ruggedness: is related to the reproducibility of the results considering different equipment (different instrument units), personnel, different lots of reagents, etc.  The BioLumix system has been demonstrated to be very rugged with high precision of test results obtained by analyzing the same microorganisms under a variety of different operating conditions including different analysts, different instrument units, and various  lots of media.
  • False negative rate: A false negative is a test in which samples that are inoculated or naturally contaminated generate a positive result in the reference method (plate count) but are negative in the test method (BioLumix). Naturally contaminated samples were tested at various specification levels, the BioLumix procedure detected the samples as being contaminated in all cases while the plate count method had a false negative result.
  • False positive rate: A false positive is a test in which a sample that does not contain the target organism generates a positive result in the BioLumix system but not in the Plate Count method. A false positive rate of 2.5% was seen in total aerobic count and no false positives were seen in the yeast and mold assay.


There is a need for rapid microbial detection technologies in order to improve the quality of products and their safety and speed up time to results. Their benefit could include significant reductions in time-to-result over conventional methods, improved sensitivity, specificity and accuracy, benefits of automation, reduced requirements for staff training, rapid product release, and lower inventory.  New rapid automated methods in microbiology need to be validated, and the BioLumix system comes with a validation book.

  • Unique validation book created for each customer.
  • Single platform testing for all assays
  • Real-time communication – early warning of contamination
  • Automated Certificate of Analysis in 48 hours
  • No product interference with ready-to-use vials with organism specific enrichment medium
  • Technology based on traditional media
  • Stackable compact instruments take up little bench-top space
  • Technical service available 24/7


Food  and  Drug  Administration  (FDA)  (2007),  21  CFR  Part  11,  Guidance  for Industry; Electronic Records; Electronic Signatures – Scope and Application. The National Formulary, Rockville, MD

United States Pharmacopeia (USP) (2008), Chapter <1223>, Validation of Alternative Microbiological Methods. The National Formulary, Rockville, MD

United States Pharmacopeia (USP) (2008), Chapter <2021>, Microbial enumeration tests-Nutritional and dietary supplements. The National Formulary, Rockville, MD

United States Pharmacopeia (USP) (2008), Chapter <2022> Microbiological procedures for Absence of Specified Microorganisms- Nutritional and dietary supplements. The National Formulary, Rockville, MD