CD-Chex CD34 is a ready-to-use, positive procedural control for enumerating CD34 positive cells by flow cytometry. Designed to resemble a patient sample, CD-Chex CD34 contains human leukocytes and erythrocytes in a preservative medium with CD34 positive cells having characteristics similar to human hematopoietic progenitor cells. The whole blood control does not need to be diluted and offers 30-day open-vial stability, eliminating the need to track thermal openings. Its long shelf life reduces the number of shipments, associated costs and time spent performing lot-to-lot correlation.