China Counting Chamber

Introduction

The Neubauer chamber is a thick crystal slide with the size of a glass slide (30 x 70 mm and 4 mm thickness). In a simple counting chamber, the central area is where the cell counts are performed. The chamber has three parts: (1) the central part, where the counting grid has been set on the glass, and (2) double chambers/two counting areas that can be loaded independently.

Neubauer chamber

The Neubauer chamber is a thick crystal slide with the size of a glass slide (30 x 70 mm and 4 mm thickness). In a simple counting chamber, the central area is where the cell counts are performed. The chamber has three parts: (1) the central part, where the counting grid has been set on the glass, and (2) double chambers/two counting areas that can be loaded independently.

Figure 1. Neubauer commercial chamber; Figure 2 Pile of glass covers, and box

Neubauer chamber’s counting grid is 3 mm x 3 mm in size. The grid has 9 square subdivisions of width 1mm (See Fig. 3). In case of blood cell counting, the squares placed at the corners are used for white cell counting. Since their concentration is lower than red blood cells a larger area is required to perform the cell count. The central square is used for platelets and red cells. This square is split in 25 squares of width 0.2 mm (200 µm). See Fig. 4-2. Each one of the 25 central squares is subdivided in 16 small squares. Fig 4-3. Therefore, the central square is made of 400 small squares.

Figure 3. Neubauer-improved chamber counting grid detail

Glass cover

The glass cover is a squared glass of width 22 mm. The glass cover is placed on the top of the Neubauer chamber, covering the central area. The glass cover leaves room for the cell concentration between the bottom of the chamber and the cover itself. The chamber is designed so that the distance between the bottom of the chamber and the cover is 0.1 mm. It is not uncommon that the glass cover remains slightly lifted when we introduce more liquid than necessary in the chamber. To avoid this, some counting chambers have two special clamps to avoid the cover glass to avoid edge-lift. If the glass cover is lifted, the distance between the chamber and the cover will be higher than 0.1 mm, and the cell counts will not be accurate.

Figure 1. Neubauer commercial chamber; Figure 2 Pile of glass covers, and box

Neubauer chamber’s counting grid is 3 mm x 3 mm in size. The grid has 9 square subdivisions of width 1mm (See Fig. 3). In case of blood cell counting, the squares placed at the corners are used for white cell counting. Since their concentration is lower than red blood cells a larger area is required to perform the cell count. The central square is used for platelets and red cells. This square is split in 25 squares of width 0.2 mm (200 µm). See Fig. 4-2. Each one of the 25 central squares is subdivided in 16 small squares. Fig 4-3. Therefore, the central square is made of 400 small squares.