Bürkner counting chamber, counter grating with 9 large squares, 1 unit(s)Brkner counting chamber, counter grating with 9 large squares Material: glass. For leucocyte and erythrocyte counting. Double counting grid. Counting grid with nine large squares for leucocyte counting. Each large square is divided into 16 group squares for erythrocyte counting. The group squares are not subdivided further. Large square: 1 mm2 Group square: 0. 04 mm2 The counting grid appears under the microscope as a grid of dark lines. In vitro