It depends on how many samples you have and what kind of equipment you have. Some automatic cell counters can supposedly distinguish between red blood cells and white blood cells, but I wasn't very impressed with what I saw at the AACR conference. One of my colleagues had a automatic cell counter that they returned because it never worked well and it was less accurate than using the hemacytometer. What we do to count WBC in animal blood is to send it off to a veterinary pathology lab and have them do it for us.

If you want to do it your self, I would use a hemacytomer and dilute the blood and count the WBC in the slides. It's labor intensive but it's very reliable, and not prone to machine error. If you are just looking for leukocytes, you can lyse the red blood cells using a RBS lysis buffer, and resuspend in PBS. This will make counting easier as there are less of other cells in the hemacytomer. Just be very careful about keeping track of initial volume, resuspension volume, and dilution factors.

You cut the tip of mouse tail and get 5-10 ul of the blood. Then, resuspend blood in 200 ul pof 3% acetic acid. After this, you can use standard chamber for counting of blood cells. You should count no less than 200 cells to obtain reliable results. The number of leucocytes can vary in dependence of many factors, such as infections, stress, food, etc. In many cases leucocytosis (leucopenia) is transitional and lasting no more than several h.

I agree with Dmitry. I will add that I use heparin coated capillary tubes to collect blood from cut tail and add a precisely measured amount (5 ul) of whole blood to 195 ul 3% acetic acid ( i.e. 1:40 dilution) and count WBC's using haemocytometer. The haemocytometer is designed so that the number of cells in one outer corner grid containing 16 squares is equivalent to the number of cells x 10e4 / ml of sample

Therefore, to obtain the WBC count by counting all four corner squares the calculation is as follows.

The total count from 4 sets of corner squares each containing 16 grid squares = (cells / ml x10e4) x 4.

1. Divide the count by 4 to get average cell count / corner grid

2. Then multiply by 40 to adjust for the 1:40 dilution in 3% acetic acid.

What about counting rbc in mice using haemocytometer?

Meaad Almowaled

Depend on the strain of mice, sex, etc.

http://jackson.jax.org/rs/444-BUH-304/images/physiological_data_000664.pdf

http://jackson.jax.org/rs/444-BUH-304/images/physiological_data_000651.pdf