Cell experiment:

Blood samples (1 mL) are obtained using a sterile Butterfly-21 needle and plastic syringe from the antecubital vein of normal healthy volunteers who have given their informed consent. They are immediately transferred to plastic tubes containing 17.3 mg of phenylmethylsulphonyl fluoride (PMSF) and 1 mL of LDS-751 at room temperature. Aliquots (25 μL) are incubated for 5 min with between 2 μL and 5 μL of undiluted monoclonal antibodies, then diluted with 0.5 mL of 1% BSA in Hepesbuffered Hanks' balanced salts solution (HHBSS) and examined by flow cytometry[2].

LDS-751 is a nucleic acid stain.

The LDS-751 permits the discrimination of intact cells from residual erythrocyte ghosts, platelets and damaged nucleated cells. The forward and orthogonal fight scattering signals of the intact cells, identified by LDS-751 staining allow a clear separation between the major leukocyte populations since the damaged nucleated cells, erythrocytes, erythrocyte cell ghosts and platelets are removed from the display[1].

[1]. Terstappen LW, et al. A rapid sample preparation technique for flow cytometric analysis of immunofluorescence allowing absolute enumeration of cell subpopulations. J Immunol Methods. 1989 Sep 29;123(1):103-12. [2]. McCarthy DA, et al. A simple flow cytometric procedure for the determination of surface antigens on unfixed leucocytes in whole blood. J Immunol Methods. 1993 Aug 9;163(2):155-60.