A-C. The PEPCK-Ins transgene. Schematic representation (A). Example of PCR screening of PEPCK-Ins transgenic mice (B). Lanes 1–5 and lanes 10–14 are PCR reactions with genomic DNA extracted from mice that developed from microinjected mouse eggs. Primers specific for the PEPCK-Ins transgene were used for lanes 1–9 (30 cycles) while primers specific for mouse insulin 1 were used for lanes 10–18 (30 cycles). Lanes 6 and 15 are PCR negative controls (no DNA added). Lanes 7 and 16 are PCR reactions to demonstrate the specificity of the primers used (wild type NOD mouse DNA added). Lanes 8, 9, 17 and 18 are half copy spiked and plasmid controls respectively (positive controls). Example of Southern Blotting for the PEPCK-Ins transgene (C). Lane 1 One copy spiked sample (100 ng Balb/c genomic DNA + 102fg PEPCK-Ins plasmid), lane 2 genomic DNA from tail tip of F2 PEPCK-Ins mouse, lanes 3 and 4 are DNA from pups which died before weaning and lanes 5–7 are DNA from still born pups. Each lane was loaded with 15μg of genomic DNA that was digested with Xba I and Pst I to release the transgene.