STUDY OF NEUBAUER’S

CHAMBER

BY: Dr.Sidra Qaiser

HEMOCYTOMETER

Hemo: blood

Cyto: cell

Meter: measurement/counter

Thus, it is an instrument used to count

the blood cells.

It includes:

a) Neubauer’s

slide

b) Cover slip

c) RBC pipette

d) WBC pipette

NEUBAUER’S SLIDE

It is the name given to a thick glass

slide. In the centre of the slide, there is

an H- shaped groove. On the two sides

of the central horizontal bar, there are

scales for counting the blood cells.

The depth of the scales is 1/10mm or

0.1mm.

Improved Neubauer Hemocytometer

NEUBAUER’S CHAMBER

Neubauer’s slide with a cover slip over it,

is called a Neubauer’s chamber.

• Each scale is 3mm wide and 3mm long.

• The whole scale is divided into 9 big

squares.

• Each square is 1mm long and 1mm

wide.

Hemocytometer

Chamber

Four

corner

squares

are meant

for WBC

counting.

Total = 64

small

squares

W

W

W

W

The central square is subdivided into

twenty five smaller squares and each of

these smaller squares is further

subdivided into sixteen smallest

squares.

These are meant for platelet and RBC

counting.

The platelets can be counted in all the

small squares of the central square.BUT

FOR CONVEINIENCE WE WILL

COUNT PLATELET IN THE CORNERS

SPECIFIED FOR RBCS.

(total of 80 smallest squares)

R R

R

R R

CALCULATION OF THE VOLUME OF WBC

SQUARES

Length of one small square = 1/4mm

Width of one small square = 1/4mm

Depth of one small square = 1/10mm

Volume of one small square

= 1/4 x 1/4 x 1/10

= 1/160mm³

CALCULATION OF VOLUME OF PLATELET

SQUARE

Length of one smaller square = 1/5 mm

Width of one smaller square = 1/5 mm

Depth of one smaller square = 1/10mm

Volume of one smaller square

= 1/5 x 1/5 x 1/10

= 1/250mm³

Each of the smaller squares is further

subdivided into sixteen smallest squares.

Length of one smallest square = 1/5 x 1/4

= 1/20mm

Width of one smallest square = 1/20mm

Depth of one smallest square = 1/10mm

Volume of one smallest square

= 1/20 x 1/20 x 1/10

= 1/4000mm³

Cell Counts by Hemocytometer

Counting Rule• Do not count cells

touching

• Bottom line

• Right line

This is to avoid

double counting.

DIFFERENCES BETWEEN RBC AND

WBC PIPETTE

RBC pipette WBC

pipette

1) It has a red bead It has a white

bead

2) It has

graduations upto

mark 101

It has

graduations upto

mark 11

3) Size of bulb is

larger

Size of bulb is

smaller

4) Size of lumen is

smaller

Size of lumen is

larger

RBC PIPETTE

WBC PIPETTE

DILUTION FACTORS

For CELL counting

Blood is filled till mark 0.5 and fluid is then

filled till mark 101.Both are thoroughly mixed.

For Platelet counting

1 part of blood is mixed in 100 parts of

Platelet fluid (Rees Ecker) , so dilution

factor for platelet counting is 100.

PLATELET COUNTING

Total no. of Cells in 80(5x16) smallest squares =

X

No. of Cells in one smallest square = X/80

Volume of one smallest square = 1/4000mm³

No. of Cells in 1/4000mm³ = X/80

No. of Cells in 1mm³ = X/80 x 4000

No. of Cells in 100 times diluted blood

= X/80 x 4000

No. of Cells in undiluted blood

= X/80 x 4000 x 100/mm³

= X x 32,000,000/mm³

• 40X for plateletcounting

FOCUSING

40x magnification