How to stain nucleic acids and proteins in Miller spreads.

The spread technique proposed by Miller and Beatty in 1969 allowed for the first time the visualization at transmission electron microscopy of nucleic acids and chromatin in an isolated and distended conformation. The final step of staining the spread chromatin is of critical importance because it can strongly influence the interpretation of the results. We evaluated different staining techniques and the most part of them provided a good result.

Unexpected distribution of KRIT1 inside the nucleus: new insight in a complex molecular pathway.

KRIT1 is an 84kDa protein that lacks any relevant catalytic domains, associated with the cerebral cavernous malformation disease. We have investigated by means of ultrastructural immunocytochemistry the nuclear distribution of KRIT1 in different cell lines, revealing its unexpected localization on actively transcribing nuclear domains such as the perichromatin fibrils and the nucleolar dense fibrillar component. These preliminary data indicate a still undescribed and unknown role for KRIT1 inside the nucleus.