654 GENERAL STAINING 



1299. Picric Acid and Methylen Blue. Stain twenty-four hours 

 or more in saturated aqueous picric acid, rinse quickly in water 

 and stain briefly in aqueous methylen blue. Rinse and dehydrate 

 rapidly. Lignified tissues, etc., lemon yellow, cellulose tissues 

 blue. 



1300. Picric Acid and Fuchsin. Pujiula {Bol. Soc. Iherica 

 Cienc. Nat., i, 1928) gives a schedule for picric-fuchsin used in 

 mixture. The combination is useful for Monocotyledon stems in 

 which the stelar and cortical tissues are hard to differentiate. 



1301. Crystal violet and erythrosin (Jackson, Stain Tech., i, 

 1926, p. 33) is useful for material in which the xylem elements are 

 small or weakly lignilied. Stain in 1 per cent, crystal violet, in 

 distilled water, for fifteen minutes, rinse quickly in water, dehy- 

 drate rapidly in 95 per cent, and absolute alcohol. Stain one to 

 five minutes in a saturated solution of erythrosin in clove 

 oil, treat with equal parts absolute alcohol and xylol one to 

 two minutes and clear in xylol. Erythrosin tends to replace 

 crystal violet in lignified tissues, hence its action needs exact 

 control. 



1302. Phloxine (or Magdala Red) and Anilin Blue. Stain in 

 phloxine (1 per cent, in 90 per cent, alcohol) three to twenty-four 

 hours, rinse in 95 per cent, alcohol and stain two to ten minutes 

 in anilin blue (1 per cent, in 90 per cent, alcohol), made up 

 freshly. Rinse in 95 per cent, alcohol and treat with 95 per cent, 

 alcohol slightly acidulated with HCl. The blue is intensified and 

 the red extracted. Wash in 95 per cent, alcohol rendered slightly 

 alkaline with sodium carbonate if the red has become too dull. 

 Wash in absolute alcohol and clear in xylol. See Chamberlain, 

 Stain. Tech., ii, 1927, p. 91. 



1303. Safranin and Picro-anilin Blue (Smith, Science, lix, 

 1924, p. 557). Stain in safranin two hours, and destain to a light 

 pink in 50 per cent, alcohol. Stain two hours in picro-anilin 

 blue (saturated solutions, in 95 per cent, alcohol, of picric acid and 

 anilin blue mixed in ratio of 78 per cent, picric acid to 22 per 

 cent, anilin blue.) Wash ten seconds in absolute alcohol and 

 clear in clove oil. 



1304. Malachite Green (or Methylen Blue) and Congo Red. 

 Used by Gregoire (see Chamberlain, p. 94). Stain in 3 per cent, 

 aqueous malachite green for six hours or more, wash in water and 

 stain in 1 per cent, aqueous Congo red for fifteen minutes. Wash 

 in water and differentiate in 80 per cent, alcohol until the green 

 stain appears through the red. Dehydrate rapidly in absolute 

 alcohol and clear in xylol. 



1305. Cyanin and Erythrosin. Best used made up in 50 per cent, 

 alcohol. Stain in cyanin five to ten minutes or longer, rinse 

 quickly in 50 per cent, alcohol and stain thirty seconds to one 

 minute in erythrosin. Rinse quickly in 50 per cent, alcohol, then 



