Mallory Staiyiing 147 



it may be of interest to recall that certain tissue elements react more 

 specifically to certain metals than to others; collagen to molybdenum, 

 and fibroglia, myoglia, neuroglia and epithelial fibers to timgsten. Lillie 

 (1952) writes that phosphotungstic acid intensifies plasma staining and 

 phosphomolybdic acid the fiber staining. The acids may be used sepa- 

 rately or together depending on the final desired effect. 



Oxalic acid is often used. Mallory (1944) claims that it makes the 

 aniline blue stain more rapidly and intensely. Baker (1958) seems to 

 agree when he suggests that oxalic acid lowers the pH, seeming thereby 

 to aid the staining of aniline blue, also of orange G. 



No polychroming or metachroming takes place in the combination 

 of dyes; they react orthochromatically in varying intensities of their 

 own colors. In Mallory's combination of stains, aniline blue (acidic) 

 stains connective tissue and cartilage; orange G (acidic) stains the blood 

 cells, myelin and muscle; acid fuchsin (acidic) stains the rest of the tis- 

 sue (including the nuclei) in grades of pink and red. This is not, how^- 

 ever, an efficient method for staining nuclei and they will fade in a few 

 years. Modifications of Mallory's using basic fuchsin, carmine or azo- 

 carmine result in more permanent nuclear staining, since the basic 

 stain reacts more reliably than the acidic one with the nuclei. The 

 method also may be preceded with hematoxylin staining for a brilliant 

 permanent nuclear stain. 



The final staining may be followed by an acetic acid wash (0.5-1%) 

 for 3-5 minutes or longer, producing more transparent sections with- 

 out altering the color. 



Method (PANTIN, 1946) 



fixation: any general fixative, preferably containing HgCL. 



solutions: 



Mallory I: 



acid fuchsin, C.I. 42685 I.O gm. 



distilled water 100.0 ml. 



Phosphomolybdic acid: 



phosphomolybdic acid 1.0 gm. 



distilled water 100.0 ml. 



Mallory II: 



aniline blue, WS, C.I. 42780 0.5 gm. 



orange G, C.I. 16230 2.0 gm. 



distilled water 100.0 ml. 



