I prepared a 1:200 dilution of red blood cells using a ~1% NaCl solution. The imaged region contains 4 nano liters of the diluted sample. This image was taken using a 40x objective.
A count is performed by counting the number of red blood cells in a few of these sections, averaging the result, and then converting back to red blood cells per microliter by multiplying times 200 (dilution) and dividing by 0.004 (sampled volume in micoliters).
For this particular sample I estimated 3.8 million red blood cells per micro liter of blood.
I tested a few different types of hemocytometer/Neubauer chambers from China and I can recommend this specific one:
There are some even cheaper alternatives but the lines are very difficult to see.
I didn't realise you could see blood cells at 40x, very interesting. I'm new to microscopy, came to it via beekeeping and have mainly been looking at pollen and bee anatomy.
Yes, it is possible!
The objective I used to take the photo is the '40x' objective. If looking through a 10x eyepiece (which is common) the total magnification when looking through the eyepiece is 400x.
If you look through a 4x objective and a 10x eyepiece then the magnification is 40x. The blood cells are visible at this magnification but they look quite small. I am specifying in case the '40x' was understood as 40x total magnification.
Very nice! The microscopes I use to teach biology are 40x objective (10x eyepiece). They're not the best, but true workhorses when it comes to durability.