USP Sample Preparation Comparison

By Jason Kircos

Many companies use in house laboratories and perform using USP methodology. In these cases, when it comes to preparing their own media and reagents, the lab needs to pay special attention to USP because the quality of the results depends on the quality of the culture media prepared. This includes accurate weighing of dehydrated components, the use of high quality (USP purified) water, completely dissolving the dehydrated media or individual ingredients, and the need to control the heating of the media to avoid damaging heat-labile components of the media. The quality control of each batch of the media is a critical concern. However, a major issue with microbiological testing is the hidden costs in labor and inventory hold time.

The BioLumix system simplifies the testing due to the pre-made vials that do not require a technician to run quality control on the vial.

Sample preparation for the USP to BioLumix is very similar, so the transition for most laboratories is very simple. The benefit that is gained is the time it takes to get results and the ease of processing samples.

One example for sample processing is Yeast and Mold, which shows the advantage of the BioLumix system. Both the USP and BioLumix sample preparations start with a 10 gram sample into 90ml of either Butterfields Buffer or Fluid Soybean-Casein Digest Medium (TSB). The sample is then tested for pH to make sure it is the optimal range (6.0-8.0). From this point the BioLumix system shows how much easier and efficient an automated system is over the traditional methodology.

For the BioLumix system, the sample is then added to the vial, the information is added to the system, the sample starts running and 48 hours later, the data is archived and completed.

Now, compare that to the traditional USP methodology. First is the need to melt the agar used to pour the plates, and the time it takes to allow the media to temper down to an appropriate temperature that does not damage any possible organisms in the product. Then you must take the sample and pipette it onto the plate, and then pour the tempered media on the plate. Next, comes swirling the media and sample to evenly distribute it throughout the plate. Finally, then use must allow it to solidify and then place in the incubator for 5-7 days. Once the incubation is complete, read the plate and record the results.

The BioLumix system gives the result in 48 hours and automatically tells the customer if it is above or below the specification level. While the traditional USP methodology needs to wait 5-7 days before results are complete.

Many other assays that use the BioLumix system reduce the time to get results much quicker than USP. For example, total aerobic count which instead of 2-3 days using traditional USP methodology, is less than 24 hours on the BioLumix system.  E. coli testing takes three days using USP methodology but only two days using the BioLumix system.

The BioLumix System is a system that fits the needs of the supplement industry in terms of speed, working with all product matrices, and automatically documenting the results in real-time, thereby reducing the labor requirement for microbiological testing.

The BioLumix system was extensively validated for dietary products and compared to the methodology described in USP <2021> and <2022>.  The validation methodology followed USP <1223> “Validation of Alternative Microbiological Methods”.  This included performance criteria such as: side-by-side comparison to the USP methodology, accuracy and precision, specificity, limits of detection and quantification, along with ruggedness and robustness, reproducibility of the results, false positivity rate and false negative rate.

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