Chris Wozniak (left) and Dan Flowers (right) are senior product managers at MilliporeSigma, working to provide high-quality and well-characterized biochemical reagents and buffer products
Recent publications highlight the low reproducibility rate of preclinical research and the issues that surround it. Various sources for this irreproducibility can be grouped into four main categories: study design, laboratory protocols, data analysis and reporting, and the actual biological reagents and reference materials used. Improvement efforts for biological reagents have primarily focused on validating antibodies and authenticating cell lines, two areas where significant improvement opportunities exist. What about buffers? Buffers are ubiquitous in life sciences and are often overlooked as a source of variability in experiments, yet they can have a significant contribution to reproducibility.
In this recent webinar, Chris Wozniak and Dan Flowers, senior product managers at MilliporeSigma, explore ways in which experimental reproducibility can be improved by simply taking a few things into consideration when using biological buffers, such as how strongly buffers may interact with metals and other biological materials. They also discuss the tools available to make buffer selection easy and share other practical tips to improve reproducibility when using biological buffers.
Read on for the highlights from the Q&A session of the webinar, and if you missed it, watch the webinar on-demand.
Q: Are there ways to extend the useful life of buffer solutions?
CW: We addressed some of the ways earlier: good storage conditions, such as in the refrigerator and also in the dark. We know that some customers might use additives like sodium azide. However, sodium azide is hazardous and needs to be handled with care. Also, it is just a bacteriostatic agent - it only limits microbial growth, it doesn’t effectively control microbial growth. In fact, I know that there are some studies that show that some gram-positive bacteria are known to be resistant to the effects of sodium azide. So, we warn that the use of additives needs to be closely considered. I also know that in the diagnostic marketplace some customers use other additives like ProClin™, a widely used preservative system, especially for in vitro diagnostics. But again, as we talked about before, it's best to use fresh solution wherever possible.
Q: Besides MES, what other buffers have potential to be affected by the polyvinyl sulfonate impurity?
DF: There are other biological buffers that could potentially, through their chemistry, create polyvinyl sulfonate. Obviously in the ethane sulfonic acid buffers there could be other buffers in which this potential impurity could occur, such as CHES, BES and HEPES. So, it’s important to understand that the impurity may have an impact on the application the customers are using the buffer for.
Q: Why are trace elements critical in buffers or other raw materials?
DF: With respect to cell culture media, I mentioned that zinc and copper have been shown to have potentially adverse effect on cell culture growth and therapeutic antibody production. Some recent white papers that have been submitted from our material characterization group have a little more detail on the potential impact of these specific trace elements. I also mentioned catalysts as a potential source of trace elements, which also could be poisonous to enzymatic activities. So, it’s really important to understand trace elements and how these can be brought into experiments through the buffers and again be part of your selection considerations.
Q: What else are reagent suppliers doing to help improve the quality of reagents used in research?
CW: At MilliporeSigma, we offer our customers a wide variety of product grades and qualities. We try our best to tailor those products to different applications, ranging from basic research to pharma and biopharma manufacturing. But, we find that some customers use the wrong products for a given application, so training is one of those essential things we are doing. This webinar is a first step in informing buffer users about this. Also, we invest a lot of time and effort, equipment and technology to minimize batch-to-batch variation and ensure our products are of the highest quality.