20 • Fixntion (chap. 1) 



navashin's fixative (Randolph, 1935): 24 hours. 



Solution A: 



chromic acid 1.0 gm. 



glacial acetic acid 10.0 ml. 



distilled water 90.0 ml. 



Solution B: 



formalin 40.0 ml. 



distilled water 60.0 ml. 



Mix equal parts of A and B just before using. At end of six hours 

 change to a new soliuion for another 18 hours. Useful for preserving 

 cellular detail in plant materials; as good as Flemming's on root tips, 

 and less erratic. Transfer to 75% alcohol. 



PERENYi's FIXATIVE [Galigher, 1934): 12-24 hours. 



chromic acid, 1% aqueous (1 gm./lOO ml. water) 15.0 ml. 



nitric acid, 10% aqueous (10 ml./ 90 ml. water) 40.0 ml. 



95% ethyl alcohol 30.0 ml. 



distilled water 15.0 ml. 



Good for eyes. Always when fixing the entire eye make a small hole 

 near the ciliary body so the fluids of both chambers can exchange with 

 the fixing fluid. For the best fixing results, inject a little of the fixative 

 into the chambers. Decalcifies small deposits of calcium; good fixative 

 for calcified arteries and glands. Trichromes stain poorly; hematox- 

 ylin is satisfactory. Wash in 50% or 70% alcohol. 



REGAUD (Kopsch) FIXATIVE [Romeis, 1948): 4-24 hours. 



potassium dichromate, 3% aqueous (3 gm./lOO 



ml. water) 40.0 ml. 



formalin 10.0 ml. 



Mix immediately before use. Recommended for mitochondria and 

 cytoplasmic granules. Tends to harden. Follow fixation by chromat- 

 ing several days in 3% potassium dichromate. Renew solution once 

 every 24 hours. Wash in running water overnight. 



rossman's FIXATIVE {LHUe , 1954B): 12-24 hours. 



absolute alcohol, saturated with picric acid . . . 90.0 ml. 

 formalin 10.0 ml. 



Good for glycogen. Wash in 95% alcohol. 



