Here are the main applications of the hemocytometer:
- To perform blood counts: blood is a fluid that naturally carries cells throughout the human (or animal) body. In turn, blood is a mix of different types of cells that carry oxygen or fight infection, among others. They are distinguishable to the experienced eye by their shape and size. So, by counting separately all the cell types visible in the hemocytometer and calculating their concentration, we can not only get the cell numbers in the whole body, but also the percentage of each of them. This is very valuable for doctors to know if you’re within the levels established for a healthy person.
- To perform sperm counts: the concentration of sperm in semen is important in order to assess the male’s fertility. For humans, values above 15 million per milliliter are normal. Because sperm cells are moving cells, they need to be immobilized prior to counting. There are also special hemocytometers that are used for sperm, due to the cells’ smaller size: Makler or MTG hemocytometers.
- To process cells for culture: when culturing cells in the lab, the medium that contains the nutrients needs to be renewed once in a while. Cells can be counted as long as they have been put in solution. This includes adherent cells for cell culture, or suspension cells if they originally come from blood, but also bacteria and yeast. A popular example is in the preparation of yeast for the fermentation of beer.
- To process cells for downstream analysis: accurate cell numbers are needed in many tests for the quantification of proteins or DNA, while some others require high viabilities for them to be valid.
- To determine the size of a cell: because the size of the hemocytometer’s squares is known, you can take a picture of your cell suspension in the hemocytometer with your microscope. Then, with a program like ImageJ, set the scale to the size of a square side (1mm for the larger squares, for example) and by drawing a line on top of a cell it will tell you what the real size is. You can even count several to have an average size.
nice explaination it was easy to understand…
Glad it was helpful!
Hi, this information is so helpful!!! Could be used for Bacteria?
Hi Jamely,
Sure, you just have to use the highest microscope magnification and count the cells in the smallest squares. There are some tips compiled in this forum that may help.
Cheers,
Maria
Hello Maria, I want to determine the MIC on bacteria, Could be Erythrosine B useful?
Hi Jamely,
Erythrosine B help you tell the difference between live and dead cells. In the forum link I sent you, they mention trypan blue; if that works, then Erythrosine B should work too. But I think the main output of MIC is (absence of) bacterial growth, which is determined by counting cells – absolute number, not ratio of live to dead? From what I have read, it looks like the most common method to do that is agar plating or broth microdilution, and you can see the results visually based on turbidity.
Hope that helps!
Maria
Hello Maria,
I am looking to potentially use the hemocytometer to determine the concentration of brine shrimp nauplii. The typical size is about 450 micrometers. Would the hemocytometer be a potential tool for this process, say by applying a ratio for the nauplii compared to the average red blood cell?
Thank you.
-Amy
Hi Amy,
You should be aware that standard hemocytometers have a depth of 100 micrometers and the grid is 3 millimeters by 3 millimeters. Way too small for you! I believe the standard for water samples, with large microscopic animals, is a Sedgewick-Rafter counting chamber. It’s much bigger and deeper. I haven’t added that chamber type to my app Hemocytometer Sidekick yet, but I’ve been thinking about it. Here’s a video explaining the chamber: https://www.youtube.com/watch?v=PMvzK5G-G7M
-Nick