DS 12.21-DS 12.211 DYE STAINS OF GENERAL APPLICATION 325 



stained. It is very diflicult to overstain in ground. If a small quantity of yellow is 

 this solution and, though the time speci- picked up by the connective tissues it will 

 fied in the formula given is from five be removed in the process of differentia- 

 minutes to one hour, no damage will be oc- tion. The time is not critical, but that 

 casioned should the sections remain over- given in the formula cited (from two to 

 night in the staining solution. After re- 10 minutes) will be found to cover the 

 moval from the staining solution the}' are range normally necessary, 

 rinsed in distilled water and accumulated A slight difiiculty will be occasioned in 

 in a jar either of distilled or tap water, dehydration through the tendency of the 

 until it is desired to counterstain them. picric acid to leave the tissues in the 

 Any of the formulas given under DS various alcohols employed. This may 

 12.221 below may be used for counter- either be prevented by dehj'drating them 

 staining, but that of van Gieson (DS in a series of 1 % solutions of picric acid in 

 12.221 van Gieson 1896), though old, is the various alcohols, or it may be ignored 

 still one of the best. Its only disadvantage completely, according to the depth of 

 is that it has a tendency to remove hema- yellow color which it is required to retain, 

 toxylin from stained nuclei, an effect If, on the contrary, it is desired to have 

 which the present method avoids. The them a very pale yellow, they may have 

 stain requires Uttle or no differentiation, to spend a period of time beyf)nd that 

 so that the sections may be placed in it necessary for dehydration in 95% alcohol 

 and examined from time to time until the to remove the unwanted picric acid. The 

 muscles are seen to be stained yellow sections are then cleared in xylene in the 

 against a red connective-tissue back- normal manner and mounted in balsam. 



12.21 CONTRASTS FOR RED NUCLEI 



12.211 Formulas Containing Picric Acid 

 12.211 Borrel 1901 see DS 12.211 Cajal 1895 (note) and also DS 23.11 Borrel 1901 



12.211 Cajal 1895 Icsl. 1905 Lee picro-indigo-carmine Lee 1905, 20 



formula: water 100, picric acid 1, iudigo-carmine 0.25 



method; [sections with red nuclei] — » water — > stain, 3-5 mins. — > water, quick rinse — > 

 abs. ale, till connective tissue clear blue 



result: muscle, green; most connective tissues, blue. 



note: See also DS 22.12 Hruby 1933. A detailed description of the use of this stain is 

 given under 12.20 above. This stain is referred to Borrel (without reference) by 

 Besson 190-1, 751; see, however, DS 23.11 Borrel 1901. Calleja (Cajal and de Castro 

 1933, 87) specifies prior staining of nuclei in DS 11.28 Orth (1892). 



12.211 Calleja see DS 12.211 Cajal 1895 (note) 



12.211 Curtis 1905 picro-naphthol black 6630,57:1038 



STOCK solutions: I. sat. aq. sol. picric acid; II. water 80, glycerol 20, naphthol blue 



black 1 

 WORKING solution: stock I 90, stock II 10 

 method: [red, preferably safranin-stained, nuclei] —> stain freshly prepared, flooded on 



slide, 10-15 mins. -^ abs. ale. till differentiated — » toluene to stop differentiation -* 



balsam 

 result: nuclei, red; cartilage, blue; other structures, yellow. 



12.211 Curtis 1905b picro-naphthol black 1863,17:003 



formula: water 100, glycerol 2, acetic acid 0.01, picric acid 0.9, naphthol blue black 0.1 

 method, etc.: as Curtis 1905a 



12.211 Domagk test. 1948 Romeis picro-thiazin red Romeis 1948, 168 

 formula: water 100, picric acid 1, thiazin red 0.01 



12.211 Dubreuil 1904 picro-methyl blue 6593,6:62 



formula: water 100, methyl blue 0.1, picric acid 0.9 



