I have checked a few protocols for preparation of gelatin-coated slides and all current ones contain chromium potassium sulfate, but some old ones didn't.

You could make it a quick mini-study: I would suggest checking APES coating [(3-Aminopropyl)triethoxysilane ] and comparing staining results (3 consecutive sections on gelatine/APES/& positive charged slides).  

I was wondering what kind of tissue you are working with and its content of acidic mucosubstances as you are using quite a long Alcian Blue staining, some methods start with 30 minutes (1% Alcian Blue in 3% acetic acid solution).

I was using positive-charged slides for Alcian Blue staining -and so did you - I wonder, why did you want to change?

If you would like to try using APES coated slides - I have used APES from Sigma. 

Good luck with your experiments.

I'm working with mouse E17.5 metatarsals, which have been previously staining well with Alcian Blue. I only tried mounting onto gelatin coated slides as heat-mediated antigen retrieval for immunofluorescence was dislodging the sections from the slide. I was hoping to salvage these sections somehow. I have seen protocols incubate sections with 0.5% cupric sulfate/saline prior to staining with Alcian Blue and was thinking this may be useful to allow the dye to attach to the tissue? The positive charge on the chromium potassium sulfate may be interfering with the binding affinity of Alcian Blue?

Thanks for suggesting APES. I may try that if this gelatin coating doesn't work out.

Hi Daisy,

Have you tried the protocol on Paraffin sections. In our lab we perform Alcian blue staining on paraffin sections from embryonic stage E12.5 and it works good. I also agree with Maria that normally the staining protocols with Alcian blue has a shorter incubation period.

Hi Chandra,

The staining works wells for both cryo and paraffin sections. I'm only experiencing problems with the gelatin coated sections with chromium potassium sulfate. I guess I may not be able to salvage these slides.