A cDNA construct encoding EGFP, cre recombinase, human diphtheria toxin receptor (DTR; HBEGF) and click beetle green 99 (CBG99) luciferase was generated, with coding sequences separated by self-cleaving 2A viral sequences. The presence of 2A sequences results in stoichiometric translation of the individual proteins. This construct was inserted at the ATG start codon of Itgax in the RPCI-24-7812 bacterial artificial chromosome by recombineering in bacterial cells. The modified BAC was linearized and injected into pronuclei of fertilized C57BL/6N oocytes and line 2 was established.