LAB - PREPARATION OF CYANMETHEMOGLOBIN STANDARD GRAPH

REAGENTS AND EQUIPMENTS

1.         Drabkin’s solution

2.         Test tubes

3.         Micropipette

4.         Spectrophotometer

Specimens

EDTA / capillary blood

Preparation of cyanmethemoglobin standard graph

Procedure

1.         Prepare and label 5 test tubes.

2.         Dilution factor use is 1:300 if 6ml of Drabkin’s solution are used. The given standard 

            concentration (cuanmethemoglobin) is 57.2 g/ dL.

3.         The contents are mixed thoroughly.

4.         Read the absorbane of each solution at 540 nm.

5.         Record the results and prepare a standard graph.

Table for cyanmethemoglobin standard graph

Number	Drabkin’s solution	Standard Cyanmethemoglobin solution	Standard Cyanmethemoglobin concentration	Absorbance reading
1	6.0	0.0
2	5.0	1.0
3	3.0	3.0
4	1.0	5.0
5	0.0	6.0

Procedure

1.         Transfer 20µl of blood to 6.0 ml Drabkin’s solution

2.         Mix well and leave in a dark place for 10 minutes

3.        Read the absorbance of each solution at 540nm using a spectrophotometer and use Drabkin’s solution as ‘Blank’.

Tests tube	Blood A	Blood B
Drabkin’s solution	6.0 ml	6.0 ml
Blood sample	20µl	20µl
Standard cyanmethemoglobin concentration	X	Y
Absorbance reading	a	b

QUESTIONS

1.                List 3 errors that can interfere with haemoglobin determinations.

2.               State the normal range for haemoglobin for Male and Female.

3.              What is the wavelength used to measure haemoglobin manually on the spectrophotometer?