By Anastacia Wienecke
Hemocytometer
(noun. /hee-mo-sai-TAA-meh-ter/)
What does it mean?
One tool that many biological researchers have in their laboratory toolboxes is a hemocytometer. This device is useful for counting the number of cells within a 10 microliter (10 millionths of a liter) volume of liquid. The hemocytometer looks like a thick microscope slide and it has a tiny grid printed on it. It also has a triangle-shaped groove – this is where the 10 microliters of liquid is deposited. This groove channels the liquid onto a tiny grid. The grid squares help us count the number of cells in a given area with high accuracy.
Photo of a hemocytometer (alternate spelling: hemacytometer) courtesy of Anastacia Wienecke. Notice that this hemocytometer has two triangle-shaped grooves and two grids. This lets us count the number of cells in two different solutions without having to clean the hemocytometer in-between.
How do I use it in a sentence?
Using a hemocytometer, I counted 300 yeast cells in 10 microliters of my solution.
Etymology
“Hemocytometer” can be broken up into three parts:
“hemo”, which comes from the Greek word “haima”, meaning blood (hemocytometers were originally designed to count red blood cells)
“cyto”, which means “cell” and originally comes from the Greek work “kytos”, meaning “hollow vessel”
meter”, which comes from the Greek word “metron” which means “measure”
Photo of cells on a hemocytometer grid courtesy of Joseph Elsbernd. Image source.
Related Terms
Hemocyte: a red blood cell
Cytometry: the measurement of the properties of cells, like quantity, size, and color