BD Pharmingen™ Leukocyte Blocking Buffer reduces nonspecific binding of cyanine-like dye conjugates to monocytes and other leukocytes

Abstract

Abstract Nonspecific binding of monocytes to certain cyanine-like dye conjugated antibodies that are commonly used in flow cytometry for cell surface staining is well known. Although lesser in extent than monocytes, other leukocyte subsets can also exhibit nonspecific binding to cyanine-like dye conjugates. This poses a challenge for multicolor flow cytometric analysis utilizing these cyanine-like dye conjugates as dye-mediated nonspecific binding can mask the real expression. Here we demonstrate that the BD Pharmingen™ Leukocyte Blocking Buffer, a blocking buffer solution, eliminates nonspecific binding of cyanine-like dye conjugates to monocytes and other leukocyte populations. In this study we show that human whole blood stained with PE-Cy5, PE-Cy7, APC-Cy7, APC-H7, PE-CF594 and other tandem-dye conjugated antibodies in the presence of this new buffer exhibits the appropriate staining profile of these antibodies to monocytes and other leukocyte subsets. We also observed that nonspecific binding of cyanine-like dye conjugated antibodies to myeloid and lymphoid subsets in mouse lymphoid tissues was diminished. BD Pharmingen™ Leukocyte Blocking Buffer, while reducing nonspecific cyanine-like dye conjugates binding, did not impact the desirable antibody-mediated specific staining. Our data also show that cell viability is not impacted. For Research Use Only. Not for use in diagnostic or therapeutic procedures. BD and Pharmingen are trademarks of Becton, Dickinson and Company or its affiliates. © 2023 BD. All rights reserved. NPM-0263 (v1.0) 1222 CF is a trademark of Biotium, Inc. Cy is a trademark of Global Life Sciences Solutions Germany GmbH or an affiliate doing business as Cytiva.