Staining nitrocellulose and PDMS array

I’m trying to find the best method to stain proteins on nitrocellulose, so we can easily see the protein on the NC membrane. I first tried Coomassie Blue which did not work very well with the NC. The Coomassie was too dark, as seen by the image below. Harold Smith gave me some Ponceau S to use, so I tried that, since it’s the preferred stain for Western Blots. After staining with Ponceau S, I was easily able to see the BSA on the NC membrane.

Now I’m trying to create a way to place a wafer on the NC. The wafer would have an array (most likely 3 membranes x 3 membranes) with different protein-drug complexes in the wells of the membranes. To prevent the drugs from mixing if they pass through the membranes, and allow for easier detection, I’m trying to adhere PDMS to NC, creating separate wells for the solutions to pass into. The PDMS infiltrates the NC fibers and spreads through the network within the membrane, preventing solutions from spreading in the NC. The first time I made an array on the NC, I had trouble removing the non-adhered PDMS squares from the NC without ripping it (NC tears very easily). I tried the experiment again, and put ample amounts of vacuum grease on the NC so it sticks to the bottom of the petri dish, and on the non-adhered PDMS squares, so they don’t move once the PDMS is poured onto the NC. The PDMS array worked much better the second time. It doesn’t look like any of the Rhodamine spread through the NC where the PDMS was adhered.

A problem I am having with the PDMS array is that it breaks the NC membrane too easily. Jess suggested I make the non-bonded PDMS squares thicker, so I have more material to grab onto when I pull the square off. She also suggested I take a piece of metal and cut groves into it, the size that I’d want the spaces in the array, and peel the metal off. If I can make a metal blocker that would be much faster and easier to make spaces on the array. Also, it would be easier to reproduce the same array each time, if I had a set piece that I used.