Abstract: An apparatus and method for automatic thin-layer cell sample slide preparation without requiring human intervention are disclosed. According to one embodiment, a cell sample is measured to derive a cell sample measurement. An estimation of total cellularity of the cell sample is determined based upon the cell sample measurement. A differential volume of diluent is dispensed to the cell sample based upon the estimation of total cellularity of the cell sample to form a cell suspension. In one embodiment, a differential volume of the cell suspension and a differential volume of cell adherent may be combined based upon the estimation of total cellularity of the cell sample to form a cell mixture. A differential volume of the cell suspension or cell mixture (if an adherent is mixed with the cell suspension) is dispensed onto a surface of a sample slide.