SECTION TWO 



Notes: 



(i) The author (Brooke) states that the greatest advantage of 

 the PVA-fixative is that it makes possible the performance of 

 satisfactory examinations for amoebiasis without the patient being 

 present. It appears that one of the major uses of the PVA-fixative 

 has been by pubhc heahh laboratories which are generally de- 

 pendent upon the delivery of specimens by mail. By using a two- 

 vial collection kit, described in the original paper, such a labora- 

 tory can perform satisfactory examinations for amoebae and other 

 intestinal parasites. Brooke also states that in attempting to 

 establish a diagnosis, the patient can be directed to collect and 

 preserve specimens passed at home, particularly those during the 

 hours of diarrhoea or dysentery. The specimens preserved in 

 PVA-fixative can be mailed to the clinic or delivered at the con- 

 venience of the patient. 



(ii) The fixative makes possible the successful staining of 

 organisms occurring in fluid stool specimens. The solution which 

 serves as an adhesive as well as a preservative and prevents loss 

 of organisms during the staining procedure, may be found to be 

 of wider application in microtechnique for collecting and pre- 

 serving other kinds of biological specimens. 



TWEEN METHOD (Gomori) 

 For lipases 



Solutions required: 



A. Tween 80 (or Crill 7) 



Note: Tween 80 is a U.S.A. product; Crill 7 is a 

 British product. 



B. Veronal acetate buifer M/5, pH 7-4 



C. Calcium chloride, anhydrous, 10% 



D. Solution A . . . . . . i ml. 



Solution B . . . . . . 5 ml. 



Solution C . . . . . . 3 ml. 



Distilled water . . . . . . 45 ml. 



Filter ; then add a crystal of thymol as a preservative 

 and store in a refrigerator where the solution keeps 

 reasonably well. 



455 



