A rapid, cost-effective method for counting human embryonic stem cell numbers as clumps.

Area of Science:

• Stem Cell Biology
• Biotechnology
• Cell Counting Methodologies

Background:

• Enumerating human embryonic stem cells (hESCs) via single-cell dissociation is laborious for high-throughput studies.
• Existing methods for hESC quantification are time-consuming and may not be cost-effective for large sample sizes.

Purpose of the Study:

• To develop a reproducible and cost-effective method for counting human embryonic stem cells (hESCs) in clumps.
• To circumvent the need for manual single-cell dissociation in hESC enumeration.
• To validate the assay's accuracy in assessing cell numbers under various conditions.

Main Methods:

• Utilized propidium iodide (PI), a DNA-binding dye, for fluorescent signal detection.
• Established standard curves correlating PI fluorescence with cell numbers for both single cells and clumps.
• Assessed assay reproducibility by seeding hESC clumps at defined densities and evaluating cell counts after different growth conditions.

Main Results:

• Demonstrated an almost identical linear relationship between PI fluorescence and cell numbers for both single cells and clumps.
• Confirmed assay reproducibility across varying seeding densities (0.05–2x10^5 cells/well).
• Showed high accuracy in estimating relative cell numbers and growth curves, validating its utility.

Conclusions:

• The propidium iodide-based assay provides a reproducible, cost-effective, and accurate method for enumerating hESCs in clumps.
• This method significantly reduces the time and effort required for cell counting in stem cell research.
• The assay is valuable for maintaining undifferentiated hESC cultures and monitoring cell growth dynamics.