Methods and compositions for rapid generation of single and multiplexed reporters in cells

A method of generating a new reporter line, said method comprising utilizing a Cre-recombinase induced cassette exchange strategy in a master cell line comprising a first reporter cassette at a safe harbor site on chromosome 13 and a second reporter cassette at a safe harbor site on chromosome 19, wherein said first and second reporter cassettes each comprise a reporter gene driven by a constitutively active promoter and multiple Lox sites to exchange the first or second reporter cassette in the master cell line with a new reporter cassette, thereby generating a new reporter line with the same isogenic background, wherein the master cell line is integrated with the new reporter cassette at a safe harbor site in the cell and wherein the new reporter cassette comprises a reporter gene driven by a constitutively active promoter and multiple Lox sites.