| (put image here or remove column) | Many of the standard methods currently used for cell
counts and viability assessments of cell suspensions,
e.g., peripheral blood mononuclear cells (PBMC), do
not provide very accurate or reliable measurements.
The Guava PCA™ System with the ViaCount assay provides
enhanced sensitivity and better precision than
optical tools such as the hemacytometer for the cell
counting and viability determination. A major benefit
of the Guava PCA is that the cell counting process can
be automated, thereby reducing the time and effort
that must be spent for the analysis. In addition, this
instrument eliminates a significant degree of operator
judgment and simplifies the validation of the method.
However, adopting a new method (instrument and
assay) into the GLP environment requires quality
testing and assay optimization to develop standard
operating procedures which must then be validated. In
this application note, we describe the use of a human
IFN-γ ELISpot to assess the precision of fluorescent cell
counting using capillary microcytometry as part of the
validation process for the Guava ViaCount assay.
These validation experiments focused on comparing
cell counts performed with trypan blue exclusion
(hemacytometer) and the Guava ViaCount Assay. The
precision of the counts was then evaluated with three
IFN-γ ELISpot Assays on PBMC preparations from five
different donors. The correlation between cell counts
and spot forming cells (SFC) were used to judge the
precision and reproducibility of the hemacytometer
and Guava ViaCount Assay. |
