Rapid production of quasi‐stable antibody‐phycoerythrin conjugates for use in flow cytometry

Abstract A simple system is described for producing quasi‐stable complexes between biotinylated antibodies and fluorochrome‐labeled streptavidin. Optimal complexes were produced by mixing biotinylated antibody and phycoerythrin‐streptavidin together at a molar ratio of 1:1 for 2 min, followed by the addition of soluble biotin to halt oligomerization. These complexes, which are stable for at least 4 h, exhibit fluorescence with cell binding which approximates that observed with standard two‐step labeling techniques. Equally important, multiple biotinylated antibodies complexed with different streptavidinfluorochromes can be used simultaneously. Cytometry 33:482–486, 1998. © 1998 Wiley‐Liss, Inc.