I am trying to isolate intact nuclei from fixed fibroblasts to perform "chromosome conformation capture" but I have some problems.
- Cells in suspension are fixed (2% PFA).
- Cells are lysed to recover intact nuclei (standard buffer that work for most cells and tissues is hypothonic solution including 0,5% NP-40 and 1,15% Triton)
- Intact nuclei are checked by staining with Methyl-pyronin green and they should appear as round blue nuclei with a little of pink cytoplasmic debris attached.
When used with fibroblasts I got only pink staining which is sympthom of inefficient cel lysis. Mechanical forces like douncers also do not help
Anyone has suggestions/experience for this problem?
Thanks and best regards