SECTION TWO 



D. Saponin, saturated (30%) in 50% 



alcohol 



Note: To prepare this solution shake the saponin, 

 with the alcohol at intervals over several hours until 

 it is all dissolved. 



Note: The saponin solution should be made up 

 freshly as and when required for use. 



E. Solution C .. .. .. 51 ml. 



Solution D . . . . . . I ml. 



Filter before use 



Note: Solution E should keep for four months at 

 room temperature. Occasional filtration may be 

 necessary to remove any sediment formed. 



Technique: 



1. Dilute fresh unclotted blood obtained by finger puncture, or 

 citrated or oxalated venous blood, in the proportion of i :io with 

 solution E in the standard leucocyte pipette. 



2. Shake the pipette mechanically, or by hand, for three 

 minutes. 



3. Fill the four chambers of two Fuchs-Rosenthal (0-2 mm. 

 deep) haemocytometers by capillary action in the usual manner. 



4. Allow the counting chambers to stand for a few minutes in 

 a moist-chamber. 



5. Count one haemocytometer while the other remains in the 

 moist chamber, using the 4 mm. objective. 



6. After counting the number of basophils in all four chambers, 

 total and average and multiply the number by the dilution factor, 

 3-13, which gives the absolute count in terms of basophils per 

 centimetre. 



Notes: 



It is stated in the original paper that a total leucocyte count 

 can be carried out simultaneously by counting two of the sixteen 

 larger squares, averaging, and multiplying by fifty. The chamber 

 should be filled immediately after shaking because if the pipette 



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