Re: Food colorings in histology

Dr. Alexander Nader at the Path. Institut Hanuschkrankenhaus in Vienna, 
Austria notes:

>>Black elder (elderberry, Sambucus nigra) was used sometimes instead of 
haematoxylin in Germany and Austria but I have no idea what it contains. It's 
still used for marmelade (I actually prefer Grandma's brand) and for 
"colour-intensification" of (cheap) red wine. It stains VERY WELL, especially 
white shirts and silk ties ;-)  <<

R.D. Lillie (in H.J. Conn's Biological Stains, 9th ed. 1977) writes that 

"the black elderberry Sambucus niger... was shown to be a mixture of cyanidin 
mono- and di- glucosides and galactosides... (Karrer P and Widmer R. 
Untersuchungen über Pflanzenfarbstoffe . I. Über die Konstitution einiger 
Anthocyanidine. Helv. Chim. Acta 1927;10:5-83.)

Kappers (Kappers CUA. Zellfärbung von chromierten Material mittels 
Holunderbeerensaft. Z. Wiss. Mikrosk. 1911;28:416-424) crushed black 
elderberries and fermented them 4 days at 26 C., later at 20 C. He then 
decanted the supernatant, extracted the residue with hot distilled water, and 
combined the two fluids. Protein was coagulated and removed. Iron chloride, 
iron alum, and potash alum premordants were tried; FeCl3 was best. Metachrome 
mixtures weakened the stain. Overnight staining in a carbol aniline solution 
followed by FeCl3 afterchroming gave the best results, comparable with a good 
carmine stain for axons, cell bodies, and nuclei."

Hoffentlich sind diese alte Zeitschriften noch in Wien erhältlich!

I hope the fabled Veltliner grape was never so dishonored!

Bob Richmond
Knoxville, Tennessee USA

<< Previous Message | Next Message >>