Dilution\Total Count

[Begin2Brew]

Ok guys need some confirmation here on whether I did this right or not.

According to Yeastcal I did a few step starters and should have ended up at 816 Billions cells at the end. My last step I crashed and decanted all but 2L. I put the started back in the stir plate to homogenize.

I took a 1ml sample and added 9ml distilled water for a 10:1 dilution. This should give me 40.8 Billion cells per ml. I then took 2ml of this solution and added another 8ml of distilled water(working with what I have here) for a second dilution of 5:1. Then for my final sample I took 1ml of this solution and added 1ml of Alkaline Methylene Violet for another dilution of 2:1. So my final dilution rate is 100:1. 10*5*2 right?

I counted 5 squares, 4 corners and 1 center. Total cell count was 128 with 6 dead.

So if I did the math right I get:
total cells = starter size (2000ml)*cells counted (128)*5* dilution factor (100)*10000

Which 2000*128*5*100*10000=1280 Billion cells??

The smack pack I used was 6 months old which yeastcal stated my starting count was 1 Billion cells at 1% viability. Maybe I had better viabilty to start out with? At 68% the numbers are closer.

Edit: I did a second count at that came out to 64 cells for the 5 squares. So if I average them I get 960 Billions cells. More what I expected.

 

[mtnagel]

If you had 816 billion cells/2L, that is 0.408 billion cells/ml (or 408 million cells/ml) of which you took 1 ml, so you had 408 million cells/ml, which you diluted 10%, so you had 40.8 million cells/ml, then diluted that 20%, so you have 8.16 million cells/ml, then you diluted 50%, so you have 408 million cells/ml. Or yes, that is a 100 dilution factor, so it is 408 million cells/ml times 1%, which is 4.08 million cells/ml.

I don't know anything about the counting, but that should be what you ended up with.