Equivalence of A Stable Liquid Glucagon Formulation With Freshly Reconstituted Lyophilized Glucagon

Inclusion Criteria: * Age 21 to 80 years old with type 1 diabetes for at least one year. * Diabetes managed using an insulin infusion pump using rapid-acting insulin such as insulin aspart (NovoLog), insulin lispro (Humalog), and insulin glulisine (Apidra) for at least one week prior to enrollment. Exclusion Criteria: * Unable to provide informed consent. * Unable to comply with study procedures. * Current participation in another diabetes-related clinical trial that, in the judgment of the principle investigator, will compromise the results of the clamp study or the safety of the subject. * Pregnancy (positive urine HCG), breast feeding, plan to become pregnant in the immediate future, or sexually active without use of contraception. * End stage renal disease on dialysis (hemodialysis or peritoneal dialysis). * Hemoglobin \< 11.5 gm/dl. * History of pheochromocytoma. Fractionated metanephrines will be tested in patients with history increasing the risk for a catecholamine secreting tumor (paroxysms of tachycardia, pallor, or headache; personal or family history of MEN 2A, MEN 2B, neurofibromatosis, or von Hippel-Lindau disease; episodic or treatment of refractory hypertension, defined as requiring 4 or more medications to achieve normotension). * History of adverse reaction to glucagon (including allergy) besides nausea, vomiting, or headache. * Inadequate venous access as determined by study nurse or physician at time of screening. * Liver failure or cirrhosis. * Any other factors that, in the judgment of the principal investigator, would interfere with the safe completion of the study procedures.