Patent ID: 9534226
Date: 2017-01-03
CPC Classifications: C12N,C12P,C12Y

Claim:
1. An expression vector or a combination of at least two expression vectors comprising at least (a) a polynucleotide encoding a product of interest or an insertion site for incorporating a polynucleotide encoding a product of interest; (b) a polynucleotide encoding a first selectable marker (sm I); and (c) a polynucleotide encoding a second selectable marker (sm II); wherein the activity of the selectable marker (sm II) is at least partially influenced by the activity of the other selectable marker and wherein the selectable markers (sm I) and (sm II) are involved in the folate metabolism, and wherein the first selectable marker (sm I) is a functional membrane-bound folate receptor and the second selectable marker (sm II) is DHFR.