Is it necessary to reverse the cross-linking of the chromatin before analysing it on the gel?
Estimation of the size of chromatin fragments without the reversion of cross-linking is not too precise. The presence of the proteins which migrates with the samples on the gel causes that the migration is longer and less precise. However if the conditions of sonication are well optimised, it is possible to avoid the long phase of the cross-linking reversion and purification; instead of that it is possible to perform only general control to check , if there is no major problem with the shearing.
