In an era of high-tech flow cytometers and automated cell counters, one classic tool remains a vital and trusted workhorse in labs worldwide: the hemocytometer, or blood counting chamber. It’s the gold standard for manual cell counting and a fundamental skill for any biologist or medical technologist.
A hemocytometer is a thick glass microscope slide with a precise grid laser-etched into its surface. When a coverslip is correctly placed on it, it creates a chamber of a very specific depth, allowing for the volumetric counting of cells.
Why is it Still Used?
- Cost-Effective: It requires only a microscope, making it accessible to any lab.
- Reliable & Direct: It provides a direct visual confirmation of your cells. You can assess viability (with a dye like Trypan Blue) and see cell morphology at the same time.
- Standardization: Despite being manual, the counting protocol is highly standardized, ensuring reproducible results across different users and labs.
The process involves loading a cell suspension into the chamber, counting the cells in specific squares of the grid, and using a simple formula to calculate the concentration of cells in your original sample. It’s a hands-on technique that builds a fundamental understanding of cell culture.
Treat your cuvettes with the same care you would any other precision optical instrument, and they will provide you with reliable data for years to come.
