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Date: | Fri, 27 Feb 1998 10:44:52 -0700 |
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From: Allen Dick <[log in to unmask]>
Subject: Hemacytometer
I understand that to determine what the level of infection per bee, the
guts of 25 bees are placed into 25 ml of water and macerated, then
shaken. After the debris settles, a drop of the broth is placed on the
hemacytometer, the slide cover put over it, and the spores, if any are
counted in the squares under a microscope (power? around 300?) , but I
forget the details and also the math. I remember that in the course Eric
& I took, that we macerated the whole abdomen for simplicity (maybe it
was the whole bee -- can't recall).
Hi Allen, Crush the whole bee. It is not neccessary to wait until the
debris settles. There are 16 groups of squares on the hemacytometer. Each
group has 16 small squares. Count the spores in 5 groups of those 16 groups
of squares. By doing this, you have counted the number of spores in 80 of
the small squares. Its probably best to count the 4 corner groups and the
middle one.
ex. if you count 8 spores in 80 small squares.
I was once given a complicated formula
to figure out the spores/bee but I found it was easier to just multiply the
#of spores above by 50000. In the ex. above, 8 spores X 50000 = 400000
spores/bee.
I think I use 400X on my microscope.
I hope this helps
Kevin Christensen
Mallaig, Alberta, Canada
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