Parallel reactions in open chip-based nanovials with continuous compensation for solvent evaporation

Area of Science:

• Analytical Chemistry
• Biochemistry
• Microfluidics

Background:

• Solvent evaporation is a major challenge in chip-based vial chemistry.
• Previous methods used closed humidity chambers to mitigate evaporation.
• Open chip-based vials require continuous solvent compensation for stable reactions.

Purpose of the Study:

• To develop an improved technique for parallel reactions in open, 15 nL chip-based vials.
• To continuously compensate for solvent evaporation using an array of microcapillaries.
• To demonstrate the suitability of the method for peptide mapping and evaluate its operating limits.

Main Methods:

• Performing parallel peptide mapping of myoglobin in 15 nL chip-based vials.
• Utilizing three enzymes: trypsin, alpha-chymotrypsin, and endoproteinase Glu-C.
• Investigating solvent evaporation from smaller vials at different temperatures to determine operating limits.

Main Results:

• Successfully performed eight parallel peptide maps of myoglobin using less than 100 pmol of protein.
• Achieved low enzyme consumption (approx. 0.1 pmol per reaction).
• Demonstrated that the continuous solvent compensation technique is applicable to reaction volumes down to 30 picoliters.

Conclusions:

• The developed technique effectively compensates for solvent evaporation in open chip-based vials.
• This method enables highly efficient parallel reactions with minimal sample and reagent requirements.
• The approach is scalable to very small reaction volumes (down to 30 pL), broadening its applicability in chemical analysis.