Problem	Possible cause	Possible solution
Human prostate digestion Low yield of epithelial cells	Low quality starting specimen.	Avoid extensive time between tissue procurement and starting of digestion.
	Over digestion of the tissue specimen.	Follow appropriate digestion time which should not exceed 16 hrs.
	Exces specimen (for example greater than 3 g).	Use a sink strainer in the first step if necessary.
	Improper straining and/or gradient centrifugation.	Care must be taken in removing the pellet from the interface after gradient centrifugation. Follow all straining steps.
DCV Staining and FACS No definitive side population	Loss of DCV after staining procedure.	Keep the samples on ice before FACS
	Concentration of inhibitor is too high causing a shift in the population.	Optimize the concentrations of dye and inhibitor based on the cell type being investigated. Always use a positive control when testing for the presence of side population in a cell type for the first time.
	No difference between inhibitor + DCV and DCV alone samples.	Check the settings in the FACS to ensure proper detection of the cells.
Radiolabeling with DHT Low radioactive detection	Loss of [3H]DHT after retention.	Maintain cold conditions once radiolabeled DHT is in cells.
	No cells retain [3H]DHT.	Use optimal concentration of inhibitor(s) and cell number.
	Cell lysate preparation	Ensure the quality of NaOH solution in order to properly lyse the cells.