Fred Hutchinson NIDDKU54 CCEH. The purpose of this procedure is to obtain a small aliquot from either a tube of blood or larger bag of cells. The small aliquot is to be a representative sample of the main body of cells contained in the tube or bag. This aliquot can then be used for cell counts or flow cytometry staining. The information garnered from the aliquot can then be extrapolated to the larger source. For this procedure use biohazard precautions.