ChemoMetec NucleoCounter, User Manual

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6 Total and viability count
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
Pipette and tips

Dispensettes if convenient

Sample vials (approx. 1,5 ml)
Remember- samples obtained from the cell suspension
must be representative.
6.1 Total cell count
To determine the total concentration of cells draw a sample of
the cell suspension into a vial. The sample size is optional as
long as at least 100µl of the stabilized lyzate is available to
load the NucleoCassette. It is important that the sample must
be representative of the cell suspension. Throughout the
examples in this User’s Guide a sample size of 200 µl is used.
Add 200 µl of the Lysis buffer to the cell sample and mix
thoroughly by turning the vial upside down 5-10 times.
Alternatively you can use the pipette.
Add 200 µl of the Stabilizing buffer and mix thoroughly. This
mixture is called the
Stabilized lyzate .
Load the NucleoCassette with the stabilized lyzate immediately
after mixing; immerse the tip of the NucleoCassette in the
stabilized lyzate and press the piston gently, see Figure 24.
The piston is pressed down to the level of the finger grips. It
is important to press the piston down slowly and to make sure
that the tip is immersed in the stabilized lyzate to avoid air
bubbles in the flow system.
The stabilized lyzate is stable for several minutes. Therefore,
it is not necessary to load the NucleoCassette immediately
after the preparation. But it is very important that the lyzate
is thoroughly mixed just before the NucleoCassette is loaded in
order to assure sample homogeneity.