Patent ID: 7374881

Claim:
A method for detecting gene expression in a cell nucleus, comprising: trapping a cell on a filter or a membrane that does not retain cytoplasmic RNA when washed with solutions that do not lyse cell nuclei, said cell having a cell membrane and a nuclear membrane; contacting the cell with a cell membrane permeation solution thereby increasing permeability of the cell membrane without increasing permeability of the nuclear membrane, wherein the membrane permeation solution is at room temperature; washing away cytoplasmic mRNA by vacuum filtration, thereby obtaining the cell nucleus on the filter or membrane; contacting the cell nucleus with a lysis buffer while the cell nucleus is still on the filter or membrane, thereby permeabilizing the nucleus without damage to mRNA within the nucleus, and obtaining a nuclear solution; recovering the mRNA from the nuclear solution; and determining gene expression in the cell based on the quantity of at least one specific recovered mRNA.