[Clinho]

Please recommend a stain suitable for dyeing of polysaccharides. I'm trying to distinguish chitosan from alginate, both bound onto a synthetic poylmer surface, but absolutely no stain binds to chitosan.

So far I tried eosin Y, methylene blue, calcofluor and a couple of fluoresceins. What other stain might be useful?

[Clinho]

Nothing so far, tried also safranin and crystal violet but no results.. Anyone might have a suggestion?

[Arkcon]

Ahem ...

http://lmgtfy.com/?q=chitosan+differential+staining

I'm sorry to do that to you, I truly am, but your question is at the same time, highly specialized and yet, chitosan nanotech is quite the hot topic, so its often mentioned in peer-reviewed literature.  You don't even need access to these documents -- I found 3 or 4 options just on the Google page.  So see if any of them help you.

[Arkcon]

Also, I've moved this topic to another subforum, and you should use the hint to direct your search.  Alginate is found in seaweed, chitosan is a component of chitin, found in arthropod exoskeletons or terrestrial fungi.  There's not much, if any, biological need for differential staining.