Patent ID: 7964350

Claim:
A process for preparing a sample containing RNA for in situ analysis of RNA or a surrogate thereof, the process comprising: contacting the sample containing RNA with a lysis mixture under conditions and for a time to produce a lysate, wherein the lysis mixture comprises: a polypeptide having protease activity, a polypeptide having deoxyribonuclease activity, and a surfactant that substantially lacks fluorescence between 300 nm and 750 nm when in use for in situ analysis of RNA or a surrogate thereof, wherein the lysis mixture is substantially free of a cation chelator; and admixing the lysate with a stop mixture at substantially the same temperature as the contacting step to form a stopped mixture, wherein the stop mixture comprises: a cation chelator effective to inactivate the polypeptide having deoxyribonuclease activity, and an inhibitor of the polypeptide having protease activity.