426 General Laboratory Aids (sec. 2) 



7. Repeat step 4. 



8. Rinse briefly in absolute alcohol, and clear in fresh xylene. Mount. 



Reclaiming and Storing Specimens 



Graves (1943) Method 



If biopsy material has dried, do not try to process it before first soften- 

 ing and rehydrating it. Place it in physiological saline solution for 1 

 hour, then fix, dehydrate, clear, and embed as usual. 



Dried Gross Specimens^ 



Tissues which have been stored in alcohol or formalin often become 

 completely or partially desiccated. If a major catastrophe arises and tis- 

 sue must be reclaimed, partial recovery can be undertaken with fair 

 returns for microscopic identification. Van Cleave and Ross {1947) re- 

 stored desiccated helminths and invertebrates to normal size by soaking 

 them in a 0.5% aqueous solution of trisodium phosphate. Trial runs of 

 this nature were made on dried formalin-fixed specimens for from 4 

 hours to 30 days, depending on hardness and size of tissue. Occasional 

 changing of the fluid seemed to help in cases of exceptionally dry pieces, 

 also warmino^ in a 40°C± oven. Increasing the concentration of the 

 phosphate did not speed recovery. Finally the tissues were washed for 

 from 30 minutes to 2-3 hours, again depending on size. 



If the specimen was fixed in a mercuric chloride fixative, the triso- 

 dium phosphate was found to be ineffective until the tissue had been 

 pretreated as follows: (1) soaked in water with enough Lugol's solution 

 added to color the solution a deep brown: 1-2 days (if the solution be- 

 came colorless, it was renewed); (2) washed in running waters: 2 hours; 

 (3) treated with 5% sodium thiosulfate: |-1 hour; (4) washed: 2 hours; 

 (5) treated with 0.5% trisodium phosphate until soft. 



Only fair results were obtained by the above methods. Considerable 

 shrinkage remained in the cells, and the nuclei stained lightly. The 

 latter condition improved somewhat after mordanting in mercuric chlo- 

 ride or potassium dichromate. 



Since recovery was based on the detergent action of trisodium phos- 

 phate, the inevitable question occurred, why not try one of the modern 

 household detergents? A 1% solution of Trend in water was added to 

 dried tissues and kept overnight in a paraffin oven at approximately 



^Special acknowledgment is made to Robert Ingeisoll Howes, Jr., lor hours of ettort in 

 developing a recovery process for the Los Alamos Medical Center, siuumer of 1959. 



