My mind's a blank. How do you do half-log dilutions using 96 well plate??
(I'm using a 1:100 dilution to begin with).

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Use a multichannel pipette to aliquot 40ul (or 80ul) into each well except the first starting well (1:100 dilution to begin with), then aliqout 10ul (or 20ul)from the starting well to the next well. Mix the solution by pipette the solution up and down 3 times, then aliqout from this well 10ul and put it into the next well and so on.

I hope this may help.

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MM: those are 5:1 dilutions, which are, at least in my book, not half-log dilutions. If someone says half-log to me, it means that I dilute by a factor of 10 every two wells. The dilution per well is then square root of 10, or a little more than 3x.

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Sorry. I thought half-log dilution means 1 in 5 dilutions, as log dilution is 1 in 10 dilution.

I think you may need to do two different dilution ratio.
First well (your starting sample 1:100) say 100ul (if this sample is 1ug/ml)
Second well 1:5 dilution 20ul of previous sample and 80ul PBS (then 0.5ug/ml)
Third well 1:2 dilution 50ul of previous sample and 50ul PBS (0.1ug/ml)
Fourth well 1:5 dilution 20ul of previous sample and 80ul PBS (0.05ug/ml)
Fifth well 1:2 dilution 50ul of previous sample and 50ul PBS (0.01ug/ml)

I hope this may help.

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Makes sense! THANKS!

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