From assay development to assay transfer (Part 2): making sure everything measures up
Nov 17, 2015
Assay transfer is a critical point in many in drug discovery and molecular diagnostics development workflows, but success isn’t always quick and easy. In this second article in our three part series on assay transfer, we discuss how having standardized pipette calibration and training programs in place, while generally a good idea, are especially critical when you’re doing an assay transfer. Additional tips for facilitating assay transfer can be found in Lab Report 7: Facilitating Assay Transfer by Controlling Liquid Handling Variables.
What do pipette training and calibration programs have in common?
You may be wondering why we’ve lumped together two seemingly different activities as a single topic for ensuring a successful assay transfer—training is for people and calibration is for instruments. However, what both of these activities share is that they help reduce variability in your data. By getting both the manual and automated sides of the transfer performing as similarly as possible, we can reduce the number of variables affecting an assay transfer, thereby increasing the chances for success.
Training makes a difference
Let’s start by focusing on pipette training and the proper technique for using a pipette. While many scientists use pipettes every day, few have been formally trained in the best ways to use a pipette to maximize precision and accuracy. The effects of this training gap can be seen in Figure 1, which shows the relative inaccuracy and imprecision arising from pipetting by a group of fifty-three QC technicians.
After a brief training session reviewing proper pipette technique—things such as optimal orientation, tip immersion depth, and aspirate/dispense speed—accuracy and precision results were noticeably improved (Figure 2).
For a scientist developing a manual assay that will later be converted into an automated one, such an improvement in performance will help make the manual assay more reproducible, which will in turn help make the data between the manual assay and the automated one more comparable, facilitating transfer.
Standardized calibration is also key
The other variable in the liquid handling equation during assay transfer? Instruments— I’m referring specifically to handheld pipettes and automated liquid handlers. When both handheld and robotic liquid handling instruments are regularly calibrated in a standardized fashion, data across instruments and across sites can be more easily compared.
The key here is standardization of calibration procedure. It’s not uncommon to find that, as organizations grow, different departments end up with the responsibility for calibrating their own pipettes and automated liquid handlers. But there’s more than one way to perform a calibration, and if the data needs to be compared between departments, having a single method or set of methods (and tolerances) for calibration will lead to better concordance in results. A great example of this can be found in our case study, Standardizing pipette calibration in a large laboratory organization results in economic and quality gains.
Again, by increasing the reproducibility of the data by ensuring optimal performance of the liquid handler, the assay transfer process is facilitated.
Reducing even more variables
If you read our previous article on assay transfer, From assay development to assay transfer (Part 1): it’s the little things that matter, you’ll have seen how understanding not just the biology but the physics, chemistry, and material science of your assay is another way to improve assay transfers. Make sure to take a look at the upcoming early spring issue of the Artel Digest, where our third and final article in this series will cover the role of effective documentation for more efficient assay transfers.
- Lab Report 7: Facilitating Assay Transfer by Controlling Liquid Handling Variables
- Video and wall poster: 10 Tips to Improve Your Pipetting Technique
- Book: The Assay Guidance Manual is freely available through NCBI. While the original publication date of the collection is 2004, many of the articles have been updated more recently.
About the Expert
Tanya Knaide is a scientist with over 10 years of experience in leading new product development projects, product launch campaigns and uncovering customer needs to develop innovative new products and services to satisfy them. As Product Manager at Artel, Tanya has led cross-functional and inter-organizational teams that span across R&D, engineering and marketing and ensured that development and marketing projects deliver benefits to the customer in a timely manner