Patent ID: 6156514
Filing Date: 2000-12-05
Classification: C07K,C12N

Abstract:
A method for producing a cell line featuring increased expression of an amino acid sequence, the method comprising:a) introducing into host cells a first vector comprising a first selectable sequence operably linked to a segment encoding the amino acid sequence,b) culturing the host cells under conditions conductive to selecting the first vector,c) isolating cells expressing the amino acid sequence at a first expression level (first high expressing cells),d) introducing into the cells expressing at the first expression level a second vector encoding the amino acid sequence,e) subjecting the cells to conditions conductive to expressing the amino acid sequence at a second expression level higher than the first expression level; andf) isolating the cells expressing the amino acid sequence at the second expression level to produce the cell line (second high expressing cells),wherein the isolation further comprises selecting cells expressing a cell-surface marker.