The Use of Cold Plasma Technology to Reduce Carryover in Screening Assays

Abstract

The accurate transfer of biological reagents represents a fundamental step in the drug screening process, and the elimination of carryover is critical for the generation of accurate measurements of biological activity. The introduction of automated liquid robotics into screening laboratories has transformed the drug screening process, enabling accurate and reproducible transfer of liquids to become a high-throughput activity, but has also introduced a new challenge for drug discoverers: to establish screening workflows that limit analyte carryover for the generation of high-quality screening data. The widespread use of pipetting tips on automated liquid handlers often necessitates the use of optimized wash protocols for removing contaminants and frequently requires the use and disposal of large quantities of organic solvents. Furthermore, many chemical and biological reagents are recalcitrant to removal from pipetting tips by treatment with organic solvents. The use of cold atmospheric plasma technology provides an alternative approach for removal of contaminants and offers many advantages over traditional decontamination protocols commonly used during biological screening. This report describes the evaluation of a cold plasma tip-cleaning system for reducing carryover in a range of biological screening assays requiring the transfer of low molecular weight compound, nucleic acid, and bacterial liquid transfers. The validation of this technology for biological screening assays is presented, and the impact of this technology for screening workflows is discussed.

Implementation and Challenges of Direct Acoustic Dosing into Cell-Based Assays

“…The success of the TipCharger to prevent cross-contamination in screening assays has also been demonstrated with low molecular weight compounds, nucleic acids, and bacterial liquid transfers. 30…”

“…The success of the TipCharger to prevent cross-contamination in screening assays has also been demonstrated with low molecular weight compounds, nucleic acids, and bacterial liquid transfers. 30 DMSO is hygroscopic and rapidly absorbs water from the atmosphere, and studies have shown that water uptake in compound DMSO solutions significantly contributes to compound degradation, precipitation, and reduction in concentration. 31,32 An open Echo source plate filled with 100% DMSO at under half capacity will equilibrate to a moisture content of over 30% within 24 h under standard laboratory conditions 23 ; therefore, storage conditions aimed at limiting hydration both prior to and during use are an important consideration.…”