Category: Automation and High-Throughput Technologies

1338-D - Long-Term Compound Storage in Acoustically Enabled Tubes: Theory and Experiment

Tuesday, February 6, 2018
5:00 PM - 6:00 PM

     Echo® enabled acoustic transfer of compounds in micro-titer plates has facilitated high throughput drug discovery at a reduced cost. Until now, these workflows used Echo qualified micro-titer plates with either 384 or 1536 wells. We have developed an acoustic tube in a 96-tube format rack that offers modular placement of tubes at each location. Each tube can be individually picked-and-placed or individually opened-and-closed with associated automation. The tubes can be accessed one at a time, all together, or in any combination. Transferring and storing compounds in DMSO from any rack position has been enabled. We evaluated the effect of fill volume and number of decapping cycles on the overall tube performance in terms of maintaining DMSO sample integrity.

     We tracked the concentration and evaporation of binary DMSO-water mixtures stored in acoustic tubes (N>1300) for 90 days. The concentration of DMSO-water mixtures was measured using ratiometric absorption via the DropSense Trinean microfluidic device. We determined the optimal two wavelengths to generate a standard curve to correlate DMSO concentration with absorption. Furthermore, DMSO evaporation and hydration were tracked gravimetrically for each tube and monitored in a time-course experiment. Single-well weight measurements are not accessible in standard micro-titer plate formats where all wells need to be weighed and/or opened simultaneously. We developed a model with empirically validated parameters that encompasses tube usage, DMSO hydration, solution evaporation, and compound concentration. For the acoustic tubes, each tube is sealed individually with a screw-on cap that can easily maintain a consistent compound concentration and DMSO concentration above 90% for 10 years and hundreds of decap-cap cycles. The half-life for DMSO hydration was determined to be ~ 5 years.

Carson Riche

Sr. R&D Engineer
Labcyte
San Jose, CA

PhD Chemical Engineering