Are you trying to perform Northern blots on cells within the collagen, or do you mean Western blots of the collagen proteins? If the first, have you tried collagenase treatment to free the cells?

Thank you for the response! The samples aren't cells, but cross-linked pads. We're trying to dissolve them without digesting them, so we aren't doing enzyme treatments.

Many years ago, I used the Nishihara technique followed by dialysis against a less acidic buffer in order to run gels. The last part is tricky as too high a pH makes the collagen re-precipitate/undergo fibrilogenesis. I think you must mean Western Blots as their should be no RNA in in the collagen?

FS Steven. Ann. rheum. Dis. (1964), 23, 300. THE NISHIHARA TECHNIQUE FOR THE SOLUBILIZATION OF COLLAGEN APPLICATION TO THE PREPARATION OF SOLUBLE COLLAGENS FROM NORMAL AND RHEUMATOID CONNECTIVE TISSUE.

" The technique consists of homogenizing the tissue in 5 per cent. w/v NaCl and repeatedly extracting in this solution until the supernatant fraction is protein-free. The tissue is then washed exhaustively with water and then suspended in 0- 22 M.NaH2PO4 with the pH adjusted to 5 - 4 (pH meter). To the suspension is added a solution containing 0 3 per cent. w/w crude oc-amylase calculated on the basis of the weights of enzyme and the original tissue. The reaction mixture is stirred at room temperature (ca. 180 C.) for 90 hrs. The suspension is then washed repeatedly with 5 per cent. NaCl followed by water and finally homogenized in a large volume of 0-2 M acetic acid. The pH of the suspension is adjusted to pH 3- 1-3- 3 with N acetic acid and the mixture stirred continuously for 24 hrs. The supernatant solution containing dissolved collagen is removed by centrifugation and the residue re-extracted with acetic acid. "