[Histonet] Safranin O staining

[Victor Wong]

Hi all,

I am working on induced chondrogenesis in cell culture.  After, induction, I put the clump of cells (pellets) in 2% agarose to make a cell block.  When the pellet did not sink to the bottom of agarose, I heated to melt the agarose again and centrifuged with higher speed. I fix the agar block in 10% formalin for an hour and then transfer to 70% alcohol and proceeded with normal paraffin procedure.  I stained the paraffin sections with Sigma Safranin O stain but got very faint or no staining.  Here is my protocol:

1. Weigert Iron Hx for 2 min
2. Acid alcohol,Scott Tap and wash
3. 0.02% fast green for 2 min
4. 0.1% acetic acid for 1 min
5. Sigma's Safranin O for 5-10 min
6. 95% alcohol then 3x 100% alcohol @3 min
7. xylene and mount

I also tried to stain the sections with alcian blue pH1.0 and the staining was not quite remarkable.  I'd like to ask if repeated heating on embedded pellet affects staining as I wanted to make sure the pellet was at the bottom of agarose.  Are there other factors affect the staining. Any comments are welcomed.

Thanks you in advance.

Victor