Calculating the amount of the desired cells in the medium ? - (Feb/20/2012 )

I have counted 2000000 cells in 1ml the cells medium using hemocytometer.

how do i load 190micL with 3000 cells (190micL with 3000 cells in each well in a 96 wells plate) ?

So you need 3,000 cells in 190ul => 3,000/0.190 = 15,789cells/ml. = 1.57x10^4cell/ml

Now you say you have 2,000,000cells in 1ml (or 2x10^6cells/ml) so you just need to dilute them to the concentration you need:
Use C1V1=C2V2 where C1= 2x10^6cell/ml, V1= is the one you need to calculate, C2= 1.57x10^4cells/ml, V2= 18.24ml (190ulx96wells).

Another way to calculate this is by total number of cells you need: 3,000 cells per well in 96 wells = 288,000 = 2.88x10^5 cells So you need to take 288,000 cell from you initial 1ml (at 2x10^cells/ml) and then bring to the final volume for a 96 well plate.

I'd recommend to prepare a bit extra to make sure you have enough. So either calculate things for 100wells, or just round up to 20ml.

hope this helps.

Thanks that is exactly what i did.
there's an on-line calculator that calculates this.

http://www.physiologyweb.com/calculators/dilution_calculator_cells_per_volume.html

Another similar calculation that i did That can be in interest, was to count the cells and than to take the desired number of cells without dillution.
It's basically the same calculation.

If i have 1000 cells in 1ml and i need to take 50 cells.
C1V1=C2V2
x=50*1/1000 => take 0.05ml (50 micL) and you will have 50 cells.

I would use v=n/c for this one, to give v=50 cells/1000 cells/ml = 0.05 ml, as you calculated without the complication of adding superfluous numbers in there.