Computer experiments to determine whether over- or under-counting necessarily affects the determination of difference in cell number between experimental groups

Computer cell counting experiments were performed in order to examine the c onsequences of over- or under-counting. The three-dimensional reaggregate c ulture laboratory environment for cell counting was used as a model for com puter simulation. The laboratory environment for aggregate and cell sizes, numbers and spatial placement in gelatin blocks was mimicked in the compute r setup. However, in the computer, cell counting was set to be either ideal ly unbiased. or deliberately biased in regard to over- or under-counting so as to compare eventual results when using the various cell counting method s. It was found that there was no affect of the cell counting methods used in determining whether there was a significant difference in cell number be tween two experimental groups. In addition. it was found that under the con ditions of these simulations, the optical disector method behaved similarly , on the average, as the ideal method of counting cell centers and in both of those cases. the average ratio between actual cell number in a flask and estimated number was close to 1.00. (C) 2001 Elsevier ScieIlce B.V. All ri ghts reserved.