A rapid method to verify single-cell deposition setup for cell sorters

Area of Science:

• Single-cell biology
• Cytometry
• Molecular biology

Background:

• Bulk techniques limit single-cell resolution.
• Cell sorters enable single-cell isolation for molecular studies (e.g., qPCR, mRNA sequencing).
• Accurate single-cell deposition in microtiter plates is crucial for expensive assays.

Purpose of the Study:

• To develop an inexpensive and rapid method for verifying single-droplet deposition by cell sorters into microtiter plates.
• To provide researchers with a reliable quality control measure before initiating costly single-cell experiments.

Main Methods:

• A colorimetric assay using horseradish peroxidase (HRP) enzyme and 3,3',5,5'-tetramethylbenzidine (TMB) substrate.
• Sorted droplets containing HRP are deposited into wells of 96- or 384-well plates containing TMB substrate.
• Color change indicates successful droplet deposition.

Main Results:

• The colorimetric method reliably detects single-droplet deposition in microtiter plate wells.
• The assay is rapid, requires no specialized equipment, and can be performed before sorting.
• Microscopy verification is time-consuming and often impractical.

Conclusions:

• This colorimetric method offers a cost-effective and efficient solution for validating cell sorter performance.
• It enhances the reliability of single-cell molecular analyses by ensuring accurate cell deposition.
• The method is accessible to researchers without specialized expertise or equipment.