MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



12. Rinse in Solution G. 



13. Immerse in Solution H for five to ten minutes. 



14. Pass through two changes of alcohol; then mount. 



Notes: 



{a) Isopropyl alcohol may be used, if desired, for every purpose 

 for which ethyl alcohol is commonly used. 



{h) The schedule at first glance appears to be complicated, but 

 the actual application is quite simple. 



{c) Slides should be agitated in all rinses and washes. 



(d) The reason for mixing so many reagents together in Solu- 

 tions F and G is that each effects certain stains and not the others. 



{e) The fast green - malachite green (Solution D) is somewhat 

 strong at first but gradually weakens as successive slides are passed 

 through it ; consequently, the time in this stage may be reduced to 

 four minutes and that of the orange 2 (Solution E) in Stage 10 leng- 

 thened to ten minutes, then equalized, and later, the changes in 

 time reversed as the orange becomes stronger after its initial weak- 

 ness. 



( / ) Approximately three hundred slides may be passed through 

 each 100 ml. of each staining solution (except the safranin (Solu- 

 tion A), which merely needs replenishment when required), and 

 rinsed before replacement becomes necessary owing to contamin- 

 ation. 



From personal communications with Professor D. A. Johansen, Pomona, 

 California, U.S.A., to whom this technique and my thanks are due. 



LACMOID - TANNIC ACID - FERRIC CHLORIDE 



For phloem and contiguous tissues: the technique gives 

 relatively stable preparations of critically stained materials 



Solution required: 



A. Tannic acid 1% aqueous. 



B. Ferric chloride, hydrated 2% aqueous. 



C. Sodium bicarbonate . . . . 2-5 gm. 

 Distilled water . . . . • . 50 ml. 



Dissolve by shaking or stirring: do not apply heat, 



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