JALOWY 



129 



JOHNSON'S NEUTRAL RED 



fixed 1-2 days in neutral formalin. 

 Treat with above reagent 5-30 min. at 

 30°C. Rinse in aq. dest.and in ammonia 

 water. After treating with 1 part neu- 

 tral formalin to 4 of aq. dest. wash in 

 running water, dehydrate, clear and 

 mount in balsam. Collagen, yellow to 

 brownish yellow; reticular fibers, black. 

 Janssen's Iron Hematoxylin recommended 

 in place of Weigert's acid iron chloride, 

 hematoxylin (Lillie, R.D. and Earle 

 W.R. Stain Teclmol., 1939, 14, 53-54). 

 Janus E'lue can be used in exactly the same 

 ways as Janus green and with equal 

 success. 

 Janus Dyes. Named after the God, Janus 

 with two faces since they often exhibit 

 two colors. Their chemistry and use in 

 histology is described by Cowdry, E. V. 

 Contrib. to Embrvol., Carnegie Inst. 

 Washington, 1918, No. 25, pp. 39-148. 



Janus green (formerly made by Grub- 

 ler) is safraninazodimethylanilinchlo- 

 ride. This is useless for staining 

 mitochondria. 



Janus green C (Hoechst) is dimethyl 

 safraninfizodimethyl anilinchloride. This 

 likewise is useless for mitochondria. 



Janus green D (Hoechst) is diethyl- 

 safraninazodimethylanilinchloride. This 

 is the most specific stain for mito- 

 chondria and is now supplied by many 

 companies both as Janus Green B and 

 simply as Janus Green. 



Janus blue G and R (Hoechst) is 

 diethylsafranin-B-naphthol and stains 

 mitochondria as well as Janus Green B. 

 The marks G and R indicate differences 

 in method of manufacture not different 

 dyes. 



Janus black D, I, II and (Hoechst), 

 of these Janus Black I is a mixture of two 

 substances Janus green B and a brown 

 dye. It colors mitochondria by virtue 

 of the former. 



Janus gray B, BB (Hoechst) are also 

 safranin derivatives but useless for 

 mitochondria. 



Janus yellow G, R, (Hoechst) likewise 

 safranin derivatives and no good for 

 mitochondria. 



Dielhylsafranin is a reduction product 

 of Janus green B. It is a red dye which 

 colors mitochondria specifically but not 

 very strongly. 

 Janus Green B (Diazingrim) is diethjd 

 .safraninazodimethylanilinchloride. Ja- 

 nus green now .sold without the qualifica- 

 tion B is usually the same substance 

 because it has become well known that 

 the dye required must have the composi- 

 tion indicated. Owing to its toxicity 

 Janus green cannot be injected into 

 living animals like trypan blue and other 

 "vital' [ stains. It is employed as a 

 supravital stain by simply immersing 



tissues in it or better by its injection 

 into the vessels of a freshly killed animal 

 the individual cells of which remain for 

 some time alive. Janus green is the 

 best supravital stain for mitochondria. 

 Janus green is also very useful for stain- 

 ing the islets of Langerhans of the 

 pancreas and the renal glomeruli of the 

 Iddney when injected intravascularly, 

 see Neutral Red. Both islets and 

 glomeruli are colored deep bluish green 

 against a background at first colorless, 

 or faintly green, and changing to pink 

 by reduction of the dye to diethyl- 

 safranin. This permits the counting of 

 islets and glomeruli in pieces of tissue 

 mounted in salt solution and observed 

 at low m.'xgnification . When the oxygen 

 is further consumed by the cells the aye 

 is reduced to a second colorless leucobase. 

 It is therefore an oxidation-reduction 

 indicator as well as a specific stain for 

 mitochondria. See Neutral Red-Janus 

 Green stain. 



Janus Red B (CI, 266), a basic disazo dye 

 of light fastness 4. Action on paren- 

 chyma described (Eniig, p. 36). 



Jaws, see Teeth and 



Jenner-Giemsa method of Pappenheim (see 

 JNIay-Giemsa). 



Jenner's Stain for Leishmania as described 

 by Craig, p. 146: To make, mix equal 

 parts 1.2% water soluble eosin (Grub- 

 ler or NAC) in acid free aq. dest. and 

 1% aq. medicinal methylene blue in a 

 flash. Shake thoroughly and let stand 

 at room temperature 24 hrs. Collect 

 ppt. on small filter paper and wash with 

 aq. dest. till filtrate is almost colorless. 

 Dry ppt. and store in dtirk at room 

 temperature. Dissolve 0.5 gm. ppt. in 

 100 cc. pure methyl alcohol (Merck's 

 Reagent). Cover smears with this 1-2 

 min. Then add aq. dest. drop by drop 

 till metallic sheen forms on surface. 

 Leave 5-15 min. longer as desired for 

 intensity. Method said by Craig to be 

 less reliable than Giemsa, Leishman or 

 Wright techniques. 



Johnson's Neutral Red stain for Nissl 

 bodies (Addison in McClung, p. 450). 

 Ripen 1% aq. neutral red 1-4 years. 

 Dilute to 0.25-0.5% before using. Differ- 

 entiate and dehydrate in the usual way. 

 Clear in 1 part xylol -|- 2-3 parts castor 

 oil. Gives good results in thick sections 

 (dOfj.) and can be employed after silver 

 methods on tissues fixed in alcohol or 

 formalin. 



Kirkman, 1. J., Anat. Rec, 1932, 51, 

 323-326 used the following unripened 

 stain after Bouin and formalin fixatives ; 

 neutral red (Coleman & Bell), 1 gm. ; aq. 

 dest., 500 cc, 1% aq. glacial acetic acid, 

 2 cc. 10-20 min. is sufficient for counter- 

 staining Weigert-Pal preparations. 



