Direct microscopic cell count

Definition

Direct microscopic cell count is a method to estimate the number of cells in a sample by observing them directly under a microscope. This technique often involves using a counting chamber or specialized slides.

5 Must Know Facts For Your Next Test

1. It requires the use of a hemocytometer or similar counting chamber to quantify cell numbers.
2. The method can be applied to both prokaryotic and eukaryotic cells, including bacteria and yeast.
3. It does not differentiate between live and dead cells unless combined with specific staining techniques.
4. It is quick and provides immediate results, but can be labor-intensive for large sample sizes.
5. Accuracy can be affected by cell clumping or uneven distribution in the sample.

Review Questions

• What equipment is commonly used for direct microscopic cell counts?
• How does direct microscopic cell count distinguish between live and dead cells?
• What are some limitations of the direct microscopic cell count method?

Related terms

Hemocytometer: A specialized slide used for counting cells manually under a microscope.

Viability Staining: A technique used to distinguish live cells from dead cells based on their ability to take up certain dyes.

Flow Cytometry: A technology that allows counting and analyzing multiple physical characteristics of single particles, typically cells, as they flow in a fluid stream through a beam of light.