You were assigned the CD4 T cell marker during the MACsFlow

You were assigned the CD4 T cell marker during the MACs/Flow Laboratory but by mistake you added 100lt of MACs anti CD4 antibody instead of 10lt prior to labeling these cells with FITCs anti CD4 antibody. Predict the % of the CD4 +ve cells, identified by Flow-Cytometry in the Negative and Positive selection fraction. Explain your reasoning

Solution

MACs (Magnetic antibody-based cell-isolation) and FLUORESCEIN ISOTHIOCYANATE (FITC) based cell isolation are cell sorting based on different principle and addition of 100lt of MACs anti CD4 antibody instead of 10lt prior to labeling these cells with FITCs anti CD4 antibody will not change much as excess antibody will not non-specifically bind to other sites. The excess will be washed out while preparing for cell sorting. So no change in CD4 +ve cells is expected.