Sedgewick Rafter Counting Chambers for counting particles and micro-organisms in clear or semi-clear liquids.

Select from our range of plastic and glass counting chambers (each includes a cover glass) and accessories.

The cell can be used with either living or preserved material.

To fill the cell, place the cover glass across the chamber top.  This allows the air bubbles to escape during the filling procedure. The sample is then taken into a 1ml wide mouthed pipette and then carefully transferred to the chamber.
Do not overfill the chamber, because the volume of the sample in the chamber must be known exactly and the cover glass must not float free, but held onto the cell walls by surface tension. During counting, water may evaporate from the chamber. To prevent gas bubble formation, a small drop of distilled water may be placed on the slide outside the cell, just touching the cell wall and cover glass. Before the cell count is made the Sedgewick-Rafter chamber should be allowed to stand for at least 15 minutes to allow algae, or other particles, to settle to the bottom.
The Grid Pattern in the base of the chamber assists the counting and calculation process, by clearly defining a known sample volume in 1μl blocks Counting in strips is easier, no need to use reticle grids or know the precise area of your field of view.