Neubauer-improved Counting Chamber with Dark Lines

Counting chambers to determine the number of particles in liquids.

The Neubauer-improved counting chamber has a standard depth of 0.1 mm. The grid consists of 3 x 3 large squares with areas of 1 mm² each. The large square in the centre is subdivided into 5 x 5 group squares with edges of 0.2 mm length each. These group squares are again subdivided into sixteen small squares of an area of each 0.05 mm x 0.05 mm = 0.0025 mm².

The lines limiting the large squares and the group squares are threefold with the central line as the actual dimension lines. The inner and outer auxiliary lines facilitate counting. They assist determining whether cells near or on the border lines are to be counted as within the area or omitted as outside of the counting area.

As the counting chamber comes with squares of different sizes it can be used for counting different types of cells. E.g. leucocytes are counted in the 4 large squares at the corners of the grid and for counting erythrocytes at least 5 group squares are normally used.

Neubauer-improved with dark lines: The grids of counting chambers with dark lines are engraved into the glass surface of the base of the chamber. When looking through a microscope these lines appear to be dark.