Dr. Kyle Roux at Sanford Research Center has developed the BioID system to help overcome methodological challenges in the identification of proximate and interacting proteins in living cells. This technology is based on the promiscuous biotin labeling of, primarily, serine residues of proteins in proximity to a bait protein conjugated with an E. coli biotin ligase (BirA) mutant. The technique has been widely adopted since first introduced in 2012. A second generation version (BioID2) incorporating a smaller ligase that functions optimally at lower temperatures has recently (2016) been introduced. BioFront Technologies has licensed BioID and BioID2 plasmids and antibodies targeting both ligases in an effort to make these powerful research tools more readily available to researchers.