Improving Automated Liquid Handling Performance For Serum-Based Assays

By Michael Grimaldi, Rachel Parshley, Heather Macken, Nathaniel Hentz, PhD., John Thomas Bradshaw, PhD.

Serum is a complex fluid component extracted from blood and is used in a variety of clinical diagnostic tests as well as biomedical research applications. The rheological properties of serum differ from ideal aqueous solutions, yet there is a need for accurate and precise assay results that doctors and scientists depend on to make critical decisions. Liquid handling precision and accuracy both directly impact assay results for both large- and small-scale operations. Automated liquid handlers (ALH) often employ liquid classes to differentiate different fluid types. Determining the optimal liquid class (LC) for this complex solution can be an arduous process made only more difficult by the fluid handling properties of the solutions themselves. In many cases, optimizing liquid class settings with the actual assay solutions is problematic due to prohibitive cost, rarity, or complexity. For these types of high-value assay solutions, users often create an analog solution that hopefully has the same liquid handling characteristics as the sample it is supposed to mimic.

Artel is developing a serum mimic solution with liquid handling properties that are analogous to several commonly used sera. This mimic will provide a serum-like reference solution that can be used to assist in liquid class optimization, volume verification, and calibration of automated liquid handlers. This solution will be the latest in the Artel MVS product line and will be specifically engineered to reduce cost and time requirements in addition to generating the most accurate and reliable results for assays that contain serum. In this study, we show the similarities of the serum mimic solution compared to various commercially available sera and the importance of choosing the appropriate liquid classes.