MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



11. Cut sections up to 5/* in thickness and float onto slides with 

 distilled water. 



12. Drain off excess water and float sections on slides with two 

 or three drops of 1% gelatine. 



13. Drain off excess 1% gelatine and leave the slides in an oven 

 at 37° C. until the sections are dry. 



14. Immerse slide in 10% formalin for ten minutes to fix the 

 gelatine; then stain in the usual manner with Sudan 3, or Scarlet 

 R, Nile blue or osmic acid, or store the slides in the 10% formalin 

 until required. 



LOW VISCOSITY NITROCELLULOSE (L.V.N.) 



For embedding tissues 



The following technique, using L.V.N, in place of Celloidin, 

 has been developed by E. H. Leach and W. Chesterman, of The 

 University Laboratory of Physiology, Oxford.* 



I am indebted to the authors and to the Oxford University 

 Press for permission to print this description of the procedure. 



Chesterman and Leach's technique using Low Viscosity Nitro- 

 cellulose (L.V.N.) offers advantages over the older method of em- 

 bedding in Celloidin, in that penetration is quicker, considerably 

 thinner sections can be cut, it is easier to use and considerably 

 cheaper than Celloidin. With L.V.N, technique large blocks, such 

 as half a cat's brain, can be cut at i^/u; small blocks 5x5 mm., 

 can be cut at 5 to jju on a paraffin microtome without any special 

 modification or attachment. 



L.V.N, is supplied damped with normal butyl alcohol; it is 

 more explosive than Celloidin and it should be handled with care. 

 When dry it will explode if hit. Exposure to sunlight should be 

 avoided. 



Solutions required: 

 Note: Solutions A and B each contain 20% of Nitrocellulose: 



*Q.y.M.Sc. Vol. 20, pt. 4, Dec. 1949. 

 26 



