Measurement of F-actin in whole blood cellular subsets

A method for F-actin measurement in a mixture of cells includes fixing the mixture of cells at a selected temperature; labeling at least one type of cells in the mixture of cells using cell type-specific reagents; labeling F-actin using an F-actin probe; and determining a content of the F-actin in each of the at least one type of cell in the mixture of cells. The method may further include incubating separate samples with or without a stimulant before the fixing of the mixture of cells; and comparing the F-actin contents in the same cell types in the separate samples.