Subjects with Type 1 diabetes and history of severe hypoglycemia will undergo screening similar to the screening done for islet transplantation including: history; physical; chest X rays; upper GI series if history of ulcer; abdominal and pelvic ultrasound with careful attention to liver parenchyma and gallbladder; EKG; stress echocardiography if older than 35, psychological evaluation; autonomic and sensorimotor evaluation. They will also have a tuberculosis skin test (PPD), and pre-transplant laboratory tests, including: serology (for hepatitis B and C, HTLV I and II, Herpesvirus 1 and 2, CMV, EBV, Parvovirus B19, RPR and HIV); first morning urine (albumin, protein and creatinine), GFR; urinalysis and urine culture; CBC, chemistry, PT, PTT, INR, C-peptide (basal and stimulated), HbA1c, , lipid profile, LFTs, thyroid profile, blood typing, PRA, MHC determination, auto-antibodies (GAD65, IA2 and insulin), and if male, prostate specific antigen (PSA). Severity of glucose lability and hypoglycemia unawareness is assessed with Clarke score, Lability index, Mage and hypoglycemia score.