[Histonet] Sirius Red (Normal Light) Yellow Colour Degradation

[André Charbonneau]

Hello to all, 

This is a quick comment I would like to mention to people completing the Sirius Red staining. If you don't seem to have the desired yellow cytoplasm ( I have seen in axolotl red blood cells) then the issue might be because you Sirius Red liquid is not longer effective. I know this might seem trivial but I was reading some previous posts that mention that the solution is good for up to 12 years. Personally, I have stained several hundred slides with the same solution of ~ 250ml of Sirius Red and gradually, the yellow found in the muscle and in the cytoplasm in normal light started becoming less vibrant. The solution can probably be kept for 12 years but it has limited amounts of usage. Once I re-made my solution, the yellow cytoplasm and muscles were vibrantly yellow again. This is different from other troubleshooting comments that were posted earlier which said to keep the slides in a shorter amount of time in the alcohols during the dehydration. Simply changing the Sirius Red would be the way to go. Both old Sirius Red and new were compared at the same time using same alcohols and acetic acids, thus removing the probability that other factors affected the colouring. 

Sirius Red 0.1% in Sat Sol. of Picric Acid: 
Direct Red 80 0.1g
Sat Sol. Picric Acid 100ml


André Charbonneau
M.Sc. Candidate
Faculty of Dentistry 
McGill University