MANUAL PHYSIOLOGY PRACTICAL - Repository:The Medical ...

FM/UOJ
Experiment 6a
MEASUREMENT OF THE HAEMOGLOBIN CONCENTRATION
The amount of haemoglobin in unit volume of blood determines the capacity to
transport oxygen. The haemoglobin concentration can be determined accurately by
clinical methods but they are laborious and time consuming. There are many easy
methods to measure it on the basis of the color index. Two of the methods will be
employed to measure the haemoglobin concentration of your blood. Talqvist method
which measure the colour of oxygenated haemoglobin; and Sahli’s method which
measures the colour of reduced haemoglobin. The haemoglobin is reduced to acid
haematin by reaction with hydrochloric acid.
Equipments:
Sahli’s haemoglobinometer.
Haemoglobin pipette
Talqvist Chart
Reagents:
Decinormal hydrochloric acid (N/10 HCl)
Methods:
Talqvist method
Make a finger puncture, collect a drop of blood on the standard blotting paper and
keep it for one or two minutes until it dries and the surface loses the shiny appearance.
Compare the colour chart and determine the haemoglobin concentration (100% = 14.5
g/100 ml) and enter the result on the board.
Sahli’s method
Take the hydrochloric acid in the Sahli’s tube to the mark 4. Collect 20 µl (mm 3 ) of
blood in the haemoglobin pipette from a finger puncture. While collecting, make sure to
hold the pipette horizontally. Do not allow air bubble while drawing blood and use a teat
to help in gentle suction. Wipe any blood on the tip of the pipette with a filter paper. If the
blood has gone above the mark in the pipette, bring it down by blotting with the filter
paper. Dip the tip of the pipette in the acid in the Sahli’s tube, near the bottom of the tube,
and gently blow the blood out into the tube and wash any residual blood in the tube by
sucking and flushing the acid. Mix the blood with acid by rolling the glass rod between
the fingers (and not by up and down strokes) and wait until the reaction between the acid
and haemoglobin is complete.
Place the tube in Sahli’s comparator and add distil water or acid little by little to dilute
until the colour matches the standard colour tubes. When the colour is close to the
standard add drop by drop and record the level every time. If the dilution exceeds the
Blood
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