ChemoMetec NucleoCounter, User Manual

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6 Total and viability count
29
6.2 Counting non-viable cells
No pre-treatment of the cell suspension is needed to count the
non-viable cells. The cell suspension is mixed to obtain a
homogenous suspension and the cells are loaded directly into
the NucleoCassette. In this way only the DNA of non-viable
cells will be stained.
Perform the measurement (for details see sections 5.2 and 5.3).
The result is displayed on the NucleoCounter and the computer
if one is connected after approximately 30 seconds.
Examine the result to make sure that the concentration of cells
is in the measurement range 5•10
3
– 2•10
6
cells/ml. Often the
result of a non-viable cell count is below the optimal
measurement range. This is generally due to the low fraction of
non-viable cells compared to the total cell concentration. The
result of the NucleoCounter should be regarded as reliable in
these cases but the operator must
be aware
that a high relative
error is associated with these results due to the nature of
count statistics.
Generally the cell suspension is not diluted prior to counting
the non-viable cells. If the cell suspension is diluted prior
to the analysis, remember to multiply with the multiplication
factor to obtain the actual concentration of non-viable cells
in the cell suspension.
6.3 Calculate viability
When both the concentration of non-viable cells and the total
concentration of cells are known, it is possible to calculate
the viability (%viability) of the cells. The calculation can
either be done manually or by use of the NucleoView software
(please refer to the NucleoView
TM
User´s Guide). For the
calculation of %viability the multiplication factors must be
taken into account according to the equation shown below.
100%
M C
M C M C
%viability
t t
nv nv t t


  
