There's got to be a better way to count cells - (Feb/17/2006 )
I'm sick of sitting under a microscope counting cells. Does anyone have a better way?
particle counters, but they aren't cheap, automatic scopes and software to drive them, there are also methods based on plate readers, and the almighty flow.
techs and grad students end up being way cheaper and easier to maintain. i think.
Our lab found a great way to count cells - it saves time, but costs more than counting them under a microscope yourself. I think that we cut our time by about 90%. Here's the link.
PCV Cell Counters
you can use cytometer:
-put 500µl PBS into cytometer for 1min
-you can then determine (by pipeting the remainder) how many volume has been aspirated (the flow rate)
-put a tube containing your cells diluted in PBS and count for 1min
-cell concentration = count/rate
-do this for all your tens of tubes
If you use the cytometer you should better add some beads with a known concentration .
Because it is difficult to know the volume aspirated while you were really acquiring.
Then, what you do is : you add to your sample a known volume of beads ( and you know the concentration of the bead). you acquire cells and beads (in the same tube). you gate on your cells and you count the number of events. idem for the beads. As you know the concentration of the beads in the tube, you can make a corelation and you know the concentration of your cells.
you can even do better, there are kits like live/dead kits from ... was it amersham? (I can check if you are interested), where you also label dead and alive cells, and it allows you to know the ratio of alive cells.
If you look in the flow cytometer manual it should tell you what the flow rates are at high, medium and low settings. Then if you acquire for a set amount of time you can work out how many cells you have per ml. You should also be able to gate on the live cells by using the forward and side scatter profiles of a pure cell population or you can use propidium iodide exclusion as a measure of viability for mixed cell populations.
All the best,
coulter counter (still takes a lot of time).
MTT assay (an assay which measures changes in colour) for measuring cellular proliferation (never used it because my boss bought the kit after i finished my counting).
THERE ARE HEAPS OF MTT ASSAYS.... it's so not fair. Some count mitotic activity, others PI staining etc etc. They're cheap and easy. You don't even have to buy it a drink first .
also check out this website for more ideas: http://www.biocompare.com/jump/2627/Viabil...y-Reagents.html