STAIN TECHNIQUE 23 



a) On animal tissues. Try the mixed stain for five minutes, 

 rinse the section in distilled water, and counterstain in Niagara 

 Sky Blue for one minute or in Aniline Blue for 30 seconds ; it may 

 be necessary to shorten or to increase the time in Niagara Sky Blue. 

 Any one of the eight mixed stains may be tried on sections of 

 earthworm and counterstained in either Niagara Sky Blue or in 

 Aniline Blue. 



b) On meristematic plant tissues. Use the mixed stain for 

 one hour, rinse in distilled water, and counterstain in one of the 

 blue dyes for one minute. 



c) On mature plant tissues. Use the mixed stain for 24 hours. 

 If there is an abundance of cellulose in the section, New Methylene 

 Blue for five minutes is the best counterstain. On fungous tissues 

 either Niagara Sky Blue or Aniline Blue gives a better contrast 

 than New Methylene Blue. 



Combinations of four stains. 



Mixed stains Counter stains 



Sun Yellow ( 10) , ( 1 ) Aniline Blue 



Orange II (5), and 



Biebrich Scarlet (2) (2) Niagara Sky Blue 



Sun Yellow (10) (3) New Methylene Blue 



Orange 11 (5), and 

 Crocein Scarlet 7B (2) 



Sun Yellow (10), 

 Orange II (5), and 

 Acid Fuchsine (1) 



Staining procedure. On invertebrate animals use the first-men- 

 tioned mixed stain for five minutes and counterstain either in 

 Niagara Sky Blue for 30 seconds or in Aniline Blue for 15 seconds. 

 On sections of vertebrate tissues the second- or third-listed stain 

 may be tried for five minutes ; counterstain either in Niagara Sky 

 Blue or in Aniline Blue. 



On sections of mature plant tissues use the first or third 

 mixture for 24 hours and counterstain in New Methylene Blue 

 for five minutes. 



