Immunostep Stepcount tubes are designed for determining absolute counts of cells in peripheral blood, bone marrow, leukapheresis and culture medium samples using flow cytometry. Stepcount tubes are a single-platform system for absolute counts, which can be used in combination with monoclonal antibodies (MoAb) conjugated with different fluorochromes, which make possible to identify cell subpopulations for which the absolute count is intended. Closed transparent tubes with a metal screen, including a white matrix at the bottom