This 25 ml FOXP3 Perm Buffer is 10X concentrated and designed for use with the FOXP3 Fix/Perm Buffer (cat# 421401). It should be diluted to 1X working solution with PBS (10 mM sodium phosphate, 150 mM sodium chloride, pH 7.2) prior to staining procedures. e.g. Dilute one (1) part FOXP3 Perm buffer(10X) to nine (9) parts PBS.