Patent ID: 7554004

Claim:
A method of producing an allelic series of modifications in a gene of interest in a mouse embryonic stem cell, comprising: a) providing: i) an in vitro culture comprising between 200 and 600 isolated mouse embryonic stem cells, each of said cells comprising a gene of interest; ii) a chemical agent capable of producing at least one modification in said gene of interest; b) treating said mouse embryonic stem cells with said chemical agent under conditions such that i) it is at least 70% probable that at least one modification in every gene in said mouse embryonic stem cells is produced, and ii) a mixture of mouse embryonic stem cells comprising said gene of interest is produced, said mixture of mouse embryonic stem cells comprising mouse embryonic stem cells having a first modification in said gene of interest, and mouse embryonic stem cells having a second modification in said gene of interest, wherein said mixture of mouse embryonic stem cells is capable of producing a mouse having a germline, and wherein said germline comprises said at least one modification; and c) isolating said mouse embryonic stem cells having a first modification in said gene of interest and said mouse embryonic stem cells having a second modification in said gene of interest, thereby producing an allelic series of modifications in said gene of interest in the isolated mouse embryonic stem cells.