Combinatorial Biology Unit, Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.|Combinatorial Biology Unit, Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.|Combinatorial Biology Unit, Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.