The new violet laser dye, Krome Orange, allows an optimal polychromatic immunophenotyping based on CD45-KO gating

Novel lymphocyte screening tube using dried monoclonal antibody reagents

We previously developed a 10-color 11-antibody combination including a viability dye, to screen T-, B-, and natural killer (NK)-cell populations in blood, bone marrow, tissue, and body fluids. Recently, Beckman Coulter has introduced a line of dried reagents that, unlike liquid reagents and cocktails, require no refrigeration, titration, or manipulation before using. We evaluated custom tubes based on our standard lymphocyte screening panel, focusing on comparative analysis, ease of use, and advantages compared with our liquid reagent set. We tested 42 samples from blood (n = 15), bone marrow (n = 17), and tissue (n = 10) with the combination CD4/CD8/KAPPA/LAMBDA/CD19/CD56/CD5/CD20/CD10/CD3/CD45 and a vital dye by both methods and compared positivity and staining intensity for each antigen. Of the 42 samples, 5 were normal samples, 3 were red cell disorders, 20 were B-cell malignancies, 5 T-cell malignancies, 4 myeloid malignancies, and the remaining 5 were other diagnoses. Dried reagents gave equivalent staining intensity results to our standard panel in a variety of sample types, with diagnoses including reactive lymphocytosis, chronic lymphocytic leukemia, and various lymphomas. Our standard panel for evaluation of mature lymphoid malignancies allows rapid assessment of any sample type while providing direct assessment of viability. The dried reagent tube reduces preanalytical work, with simple addition of sample and the viability dye to the tube, saving time, reducing potential errors, and obviating need to titrate and monitor individual antibodies. With a shelf life of at least 12 months, the reagents also offer potential savings in reagent costs by reducing wastage due to expiration or tandem breakdown in standard liquid formulation.

Collection of in vivo transmigrated neutrophils from human skin

A wealth of knowledge on the life and death of human neutrophils has been obtained by the in vitro study of isolated cells derived from peripheral blood. However, neutrophils are of main importance, physiologically as well as pathologically, after they have left circulation and transmigrated to extravascular tissues. The journey from blood to tissue is complex and eventful, and tissue neutrophils are in many aspects distinct from the cells left in circulation. Here we describe how to obtain human tissue neutrophils in a controlled experimental setting from aseptic skin lesions created by the application of negative pressure. One protocol enables the direct analysis of the blister content, infiltrating leukocytes as well as exudate fluid, and is a simple method to follow multiple parameters of aseptic inflammation in vivo. Also described is the skin chamber technique, a method based on denuded skin blisters which are subsequently covered by collection chambers filled with autologous serum. Although slightly more artificial as compared to analysis of the blister content directly, the cellular yield of this skin chamber method is sufficient to perform a large number of functional analyses of in vivo transmigrated cells.