Stain indexes (SI) of cells stained with lyophilized antibodies were higher than the liquid counterparts.

Stain index, calculated as D/W, where D  =  difference between the medians of the positive and negative populations and W  =  spread (2× rSD) of the negative population, is indicated for each antibody-fluorochrome combination ± SEM. The SI was calculated at one time point. Paired t test or Wilcoxon signed rank test was performed, *P<0.05, ***P<0.001.