To perform the total cell counts in BAL fluid recovered from an OVA-induced mouse asthma model, we usually dilute BAL fluid 1:1 with Trypan Blue, then count 4 corner squares of hemocytometer. One suggests me to use the formula below:
Total cells (104/ml) = (X:4)*10*50*F/Y
in which, X: total cells counted in 4 squares, F is dilution factor, Y is the volume of BAL fluid (uL)
Is there anyone use the same formula for total cell count? Can you explain to me the meanings of the numbers "10", "50" ? Thank you.
Tu Trinh, there are many different formulas with the same results, try to use this simple formula: tt cells (cells/ml) = X: 0.4 x F x 1000
Whereby X is total cells counted in 4 squares, F is dilution factor, 1000 is 1000µl (1ml)
Above formula originates from this formula: tt cells (cells/µl) = X : (4 x 0.1 x 1/F)
Surface 4 squares is: 4 x 1mm² = 4mm²
chamber depth: 0.1mmdilution (1/F) e.g. 1/10
Thank you for your answer! It really helped me to understand the formula clearly.
Actually, in our laboratory, for total cell count in BAL fluid collected from mice, they use the formula as described previously in my question. I tried to calculate the total cell count by using both formulas, and got 2 different results. Among 2 formulas, I found some similarities as well as differences. The remaining thing that made me confused was multiplication by 50.
I wonder if BAL fluid had any specific characteristic as compared to other liquid samples? If you have any experience in this field, please share your opinion with us!
Hi Tu, what is your hemocytometer? If it is " Neubauer Chamber", I also don't understand why exists so formula, I've never seen. I have tried with different formulas and got the same results. I send you enclosed file about Hemocytometer.
You also can try here http://www.hemocytometer.org/hemocytometer-calculator/
The simple way to count cell/ml = X/4*F*104 cells /ml first then multiply the volume of BAL fluid to get the total cell counts. X is the total cells in four squares, F is dilution factor which is 2 in your case.
Hi Dung and Laurie,
Once again, thank you all for your above answers. Finally, I found the answer to my question. The formula is still the same basically, just as you mentioned previously. It is due to our procedure while collecting BAL fluid, following by dilution and consequent steps. Thus, some parameters have been adjusted but the results are still constant as the original formula.
- Best.