CD-Chex CD117 Plus is a ready-to-use control for evaluating surface antigens, including CD117, CD25, and CD71, with monoclonal antibody binding by flow cytometry. It was developed with characteristics similar to abnormal peripheral blood leukocytes often found in a hematolymphoid neoplastic patient sample. The assay provides percent-positive values for CD117, CD25 and CD71 on abnormal and total leukocytes. Abnormal leukocytes are distinguishable from normal leukocytes on the basis of light scatter properties and a low level of CD45 expression. It is a positive procedural control designed to monitor reagent staining, erythrocyte lysis, sample preparation, and instrument performance. CD-Chex CD117 Plus is compatible with BD Biosciences and Beckman Coulter flow cytometry systems.