2.7. Spotting test
To compare the effect of manual and automatic counting, a spotting test
was applied. Briefly, the concentration of yeast cells in the solution
was calculated through the haemocytometer formula according to the
results of the manual counting and the “Yeast Counter” macro. Samples
with the maximum concentration were taken and diluted to
2×107 cells per
ml, which were subsequently subjected to 10-fold dilutions. Five
microlitres of each dilution, whose concentration ranged from
2×107 to 2×103 cells per ml, were
spotted onto YPD solid media and incubated at 30 °C for 3 to 5 days.
After incubation, comparisons between the manual and automatic groups
were performed, in which extra care was taken for the spots with the
fewest cells (Figure 2).