170 LABORATORY COURSE IN SERUM STUDY 



(Sodium citrate 1 gram, sodium chloride 0.5 gram, water 100 c.c.) 

 Centrifugalize and wash once in salt solution. With capillary pipette 

 remove the upper layer of the sediment which will contain most of the 

 leucocytes. 



3. Serum. Collect about 10 drops of blood in Wright capsule. 1 

 Seal the dry end in the flame and centrifugalize to obtain serum. 



Use portion of serum to make control pool, mixing serum from 5 

 to 10 different individuals. 



TEST 



Use capillary pipette l with mark about 2 cm. from the tip. Take 

 up first serum to the mark, then air, then leucocytes to the mark, then 

 bacteria. Mix the reagents in a watch glass and again draw into the 

 pipette and seal the tip. Incubate one half hour. Blow out contents 

 of capillary, mix thoroughly and make smears. Stain with Jenner's 

 stain 4 minutes, wash and blot. 



Each student makes test with his own serum and with a control 

 pool which does not include his own. 



The opsonic index is the ratio between the phagocytic average 

 of the specimen with the patient's serum and of that with the 

 normal pool, expressed as a decimal, i.e. 



" Normal " specimen phagocyte average 2.5 

 Patient's specimen phagocyte average 3.75 



Opsonic index 1.5 



If the figures for normal and patient were reversed, the index 

 would be 0.66. 

 Materials : 



Staphylococcus suspension. 

 Citrate solution. 

 Wright capsules and pipettes. 

 Jenner's stain. 



LESSON XXVIII 



DIFFERENCE IN HEAT STABILITY BETWEEN NORMAL AND 

 IMMUNE OPSONINS OR BACTERIOTROPINS 



PREPARE materials bacterial (staphylococcus) emulsion 

 leucocytes and serum as for opsonin test by Wright's method. 



1 See Lesson XIII, page 88. 



