Hib19 apc mouse anti human cd19

Peripheral blood samples from CLL patients were collected and viably frozen as part of an IRB-approved tissue banking protocol at the Dana-Farber Cancer Institute and all patients signed written informed consent prior to having the sample drawn. For samples with white blood cell count <25 K or absolute lymphocyte count <20 K, B cells were purified using the Easy Sep Human B cell Enrichment Kit (StemCell Technologies Inc.) according to the manufacturer's instructions. Following thawing, sample purity was confirmed by flow cytometry monitoring CD5/CD19 expression on a BD FACSAria II (antibodies: BV421 mouse anti-human CD5, #562646 and HIB19 APC mouse anti-human CD19, #555415, both from BD Pharmingen). Gender, age of diagnosis, and relevant genetic/immunophenotypic features of each sample are included in Supplemental Table 1. Normal B cell samples were harvested and purified from discarded material donated by normal healthy adults through the Kraft Family Blood Donor Center at the Dana-Farber Cancer Institute and Brigham and Women’s Hospital. Ten milliliters of peripheral blood was purified by Ficoll gradient, and B cells were enriched in the sample with a negative selection cocktail (RosetteSep, StemCell Technologies #15024).