Doing more with fewer resources is the name of the game in any business. One of the best tools for cutting through the early stages of assay development, when one doesn’t know what assay parameters are critical and which aren’t, is the use of a multifactorial design of experiments (DOE). DOE allows assessment of multiple factors rather than the traditional “one-factor-at-a-time” (OFAT) approach. DOE is efficient and allows moving rapidly through many potential factors in a cell-based assay (cell culture conditions, best buffer characteristics, incubation times, etc.) to figure out which are critical and which are not. DOE allows the exploration of multiple-factors-at-a-time (MFAT) which allows us to run a few experiments and draw conclusions about multiple assay parameters.

DOE is not a new science. It got its start in the early 1900s in the agricultural industry when the renowned R.A. Fisher and his coworkers outlined the necessary statistics for MFAT experimental designs. Industry took this statistical approach and started using it in the chemical and process industries in the 1950s and through the 1970s. In the next 20 years, Taguchi and others worked out screening methodologies to help identify critical process parameters.

Fast forward to today and you will hear bioassay development groups talk about how DOE has changed their approach to method development. For the past 15 years many of us began using DOE at the very last stages of method development, during the robustness studies to support our validation studies. Now many companies are using this approach to quickly move through the earliest stages of bioassay development.

If you are interested in learning more about DOE – you can google the topic. My favorite website can be found here, which is an entire college course explaining the basics of DOE. This site is geared toward engineers and might be a bit boring.

For more fun and discussion on this topic and others, join us at the upcoming BEBPA 2024 Hybrid European Bioassay Conference scheduled for 25-27 September. View our full agenda here. At this conference you will hear two talks about the use of DOE in the development of biological potency assays.