74 Botanical Microtechnique 



quick rinsing in five changes of distilled water at 1-niin. intervals, 

 then 4 hr. in stain. The material becomes stained solid black and must 

 be differentially destained. The destaining solution removes the stain 

 rapidly from cytoplasm, less rapidh from plastids, and slowly from 

 chromatin and from the active tips of mycelium. The destaining 

 action should be observed under a microscope and stopped by 



STAINING CHART VI 



Iron Hematoxylin 

 Pre-Staining Operations as in Chart I 



resin and 

 cover glass 



t 

 xylene III 



t 

 xylene II 



t 

 xylene I 



t 

 carl)()l- 



xvlene 



t 

 absolute 



akohol II 



t 

 absolute 



alcohol I 

 t 



akohol 



t 



70% 



alcohol 



t 

 50% 



alcohol 



t 

 30% 

 — > akohol 



4% iron alum 



4 hr. 



i 

 dist. water 



5 changes 

 1 min. intervals 



hematoxylin 



4 hr. 



i 

 dist. water 

 3 changes 



destaining reagent 

 uinil cliffcrcntiated 



i 

 dist. water 

 3 changes 



i 

 running 

 tap water 



5 min. 



washing first in disiilled water, then i)\ prolonged washing in luiuiing 

 tap waler. Dehydration and subsec|uent processing lollow as shc^wn 

 on the chart. In the linished slide, chromosomes, the chromatin of 

 resting nuclei, middle lamella, and active mycelia should he blue- 

 black, whereas the cell walls and cytoplasm shoidd be practically 

 colorle-ss. A finished, covered i)rei)aration may be destained by soaking 

 off the cover glass, nnming the slide back through the series into 

 water, then innnersing in the destaining solution. If a preparation is 



