Evaluation and comparison of four reticulocyte enrichment procedures.

Four reticulocyte enrichment techniques were compared: differential centrifugation, and density gradient centrifugation with phthalate esters, Percoll-Renografin (PR), and silicone oil. The reticulocyte yields were 2.6, 7.4, 13.5, and 13.1 percent, respectively. The differential centrifugation procedure did not separate a statistically significant higher number of reticulocytes than were counted in an unseparated sample. The PR density gradient procedure was the best for our needs because it yielded the highest number of reticulocytes and was the easiest and quickest of the four procedures to perform; however, the method requires a high-speed centrifuge.