MANN'S FIXATIVE 



192 



MASSON'S TRICHROME STAIN 



cause the particles can be seen within 

 the cells and the amounts of manganese 

 in the tissues can be determined by 

 chemical analysis. 



Mann's Fixative is equal parts 1% aq. osmic 

 acid and sat. corrosive sublimate in phys- 

 iological salt solution (0.85% NaCl). 

 It is a good way to apply osmic acid for 

 the blackening of fat. 



Mann's Methyl Blue-Eosin Stain. This 

 is used for protozoa and for inclusions 

 caused by viruses. Sections are de- 

 parafhnized, stained 12 hrs. in 1% aq. 

 methyl blue 35 cc, 1% aq. eosin 45 cc. 

 and aq. dest. 100 cc. They are then 

 rinsed in 95% ale, dehydrated cleared 

 and mounted. See Alzheimer's Modi- 

 fication of Mann's method. 



Manometer for capillary blood pressure, 

 see Landis, E. M., Am. J. Physiol., 

 1926, 75, 548. 



Marchi Method. For degenerating nerve 

 fibers. Modification by Swank, R. L. 

 and Davenport, H. A., Stain Techn., 

 1935, 10, 87-90. Details provided by 

 Dr. J. L. O'Leary. Degeneration time 

 of approximately 14 to 20 days. Kill 

 animal by overdose of nembutal or some 

 other barbiturate given intraperi- 

 toneally. Open left ventricle, insert 

 cannula into aorta and perfuse with 

 2.5-5% anhydrous (10% crystalline) 

 magnesium sulfate solution containing 

 2-3% potassium bichromate. Imme- 

 diately afterwards remove the brain 

 and spinal cord and put into 10% 

 formalin for 48 hrs. Place slices 3 mm. 

 thick directly, without washing, in : 

 1% aq. potassium chlorate, 60 cc. ; 

 1% aq. osmic acid, 20 cc. ; glacial acetic 

 acid, 1 cc. ; 37% formaldehyde (Merck's 

 reagent), 12 cc. Use about 15 volumes 

 of this fluid to 1 of tissue. Agitate and 

 turn over daily. After staining for 7-10 

 days, wash in running water, 12-24 hrs., 

 dehydrate in 70% and 95% and absolute 

 alcohol and imbed in low viscosity nitro- 

 cellulose as described by Davenport, 

 H. A. and Swank, R. L., Stain Tech., 

 1934, 9, 134-139. See Celloidin Im- 

 bedding. Cut 40m sections serially, 

 mount on slides, dehydrate to toluol, 

 placing chloroform in absolute alcohol 

 since low viscosity nitrocellulose is 

 soluble in absolute alcohol. Clear in 

 toluol. Mount in clarite X dissolved 

 in toluol. See these authors (Stain 

 Techn., 1935, 10, 45-52) for artifacts 

 and effects of perfusion in Marchi 

 technique. Rasmussen, G. L., Anat. 

 Rec, 1944, 89, 331-338 has elaborated a 

 very useful cellophane strip method for 

 preparation and study of Marchi serial 

 sections. 



Marchi's Fluid. Miiller's Fluid, 2 parts; 

 1% osmic acid, 1 part. Fix 5-8 days; 



wash in running water. Employed to 

 blacken degenerated nerve fibers. See 

 Nerve Fibers. 



Method, underlying mechanisms in- 

 volved (Swank, R. L. and Davenport, 

 H. A, Stain Techn., 1934, 9, 11-19; 

 1935, 12, 45-52). 



Marine Blue V, see Anilin Blue. 



Marino's Stain for malaria plasmodia is de- 

 scribed in detail by Craig, p. 286 who 

 states that it gives excellent results; 

 but, owing to its complexity, is little 

 used for routine blood examinations. 



Marrow, see Bone Marrow. 



Marshall Red (British Drug Houses Ltd), 

 a disazo dye. Stain sections in sat. 

 aq. solution 20 min. Rinse in aq. 

 dest. Stain in sat. Victoria Green G 

 in 70% alcohol 30 min. Rinse in 95% 

 alcohol, dehydrate, clear and mount 

 in usual way. Myofibrils sage green, 

 nuclei crimson. Advised also for retina 

 (H. G. Cannan, J. Roy. Micr. Soc, 

 1941, 61,88-94). 



Martius Yellow (CI, 9) — Manchester yellow, 

 naphthol yellow — An acid nitro dye 

 employed by Pianese (G., Beitr. z. 

 Path. Anat. u. AUg. Path., 1896, Suppl. 

 I, 193 pp.) for investigating cancer 

 tissue in association with acid fuchsin. 

 Conn (p. 44) reports good results in 

 staining of plant tissue with CC product. 



Masson's Gelatin Glue. Method for mak- 

 ing sections stick to slides (Masson, 

 P., Am. J. Path., 1928, 4, 181-212). 

 Dissolve 0.05 gm. sheet gelatin in 20 

 cc. aq. dest., warming gentlj'. Filter a 

 large drop on each slide on warm plate. 

 Float paraffin sections on drops. When 

 drops spread place slides upright to 

 drain but do not permit drying. Blot 

 and transfer to dish containing formalin 

 (so arranged that vapor only will act 

 on slides) in oven 45-50 °C. For sub- 

 sequent staining 20 minutes in hot vapor 

 is enough. For silver treatment over- 

 night is suggested. 



Masson's Trichrome Stain — Written by 

 Pierre Masson, Dept. of Pathology, 

 University of Montreal, Montreal, 

 Canada. October 24, 1951— The prin- 

 ciple established by F. B. Mallory in his 

 famous method of employing acid 

 fuchsin, phosphomolybdic acid, anilin 

 blue, orange G. can be advantageously 

 applied to other acid dyes yielding a 

 more specific staining of the chromatin. 

 It then gives a very instructive com- 

 bination of tints. 



Due to the intensity of the staining, 

 the sections must be thin; 5^ is opti- 

 mum. In order to prevent swelling of 

 the collagen and its deformation during 

 the desiccation, the sections must not 

 be left too long (20-30 sec.) on the 

 warmed water, or gelatin, especially 



