4 replies to this topic

[kiana27]

Hello, I have a doubt regarding the seeding specific number of cells after counting with Hemocytometer. If for example we have 10ml of cell suspension, we take few ul of the suspension and count with Hemocytometer and the count is 300,000 (it means this 300,000 is in 1ml). If we want to seed 200,000 cells, what to do? Do we need to calculate the number of cells in 10 ml first which will be 3000,0000 cells and take 0.066ml OR we should consider the number of cells from Hemocytometer (300,000/ml) and take 0.66ml ? It would be great if someone can help me with this with some kind of explanation. Thank you very much

[leelee]

So you counted your cells and you have 300,000 (3x10^5) cells per ml. This means you have 3x10^6 cells in your 10ml (not 3x10^7 like you've said above).

It really is up to you to figure out if it is easier for you to think in terms of concentration of cells (that is, 3x10^5 cells/ml) or in total cell numbers (3x10^6).
You could use c1v1=c2v2 if you are happier to think of it in terms of concentration.

But either way you work it out, you should still come to the same volume of cell suspension. I think your confusion with the number of cells in 10ml is steering you wrong here.

You are right in that there will be 2x10^5 cells in 660ul of your cell suspension.

Don't know if that helps you

[kiana27]

Thank you very much for reply, that 3x10^7 is a typo...considering that the number of cells are 3x10^6 in 10ml and we want 200,000...shouldn't we take 0.066ml (66ul)?

[casandra]

kiana27, on 28 October 2012 - 11:25 AM, said:

Thank you very much for reply, that 3x10^7 is a typo...considering that the number of cells are 3x10^6 in 10ml and we want 200,000...shouldn't we take 0.066ml (66ul)?

nope, it's as what leelee says (and it's much easier to use the formula)....or you can always try a little bit of logic or visualisation (for math atheists like myself) :

if you have 3,000,000 cells in 10 ml...then
    you have 300,000 in 1 ml..
             and  30,000 in 100 ul...... therefore
     only about 20,000 in 66 ul

[madelingirly]

Dear
kiana27

I guess it is the same,
if u will calculate it in 10 ml it must give u thr same number as if u calculate it in 1 ml.
Math is the same here, if it is not the same, this means that u r making some mistake in calculation.
so for me it is easier to go for 1 ml calculation, better than adding extra zero then remove it again by division