This is a phase I, open-label, dose escalation study in healthy adult volunteers. Eligible volunteers will be admitted to a phase I unit for study infusion and be discharged after collection of a 24 hour post infusion sample. Thirty subjects are anticipated to be enrolled. There will be five cohorts of 6 subjects each. A single dose of human monoclonal antibody MBL-HCV1 will be administered on Day 0 and subjects will be followed for 56 days. Dose escalation to the next cohort will occur after review of safety data by the principal investigator, sponsor and an independent safety monitor through day 10 for all subjects in a cohort. Assessment of safety will be determined from vital sign measurements, physical examinations, hematology, chemistry and urinalysis laboratory testing, electrocardiograms, use of concomitant medications and review of treatment-emergent adverse events should they occur. Subjects will be evaluated at study visits on days 0, 1, 2, 3, 7, 14+/-1, 28+/-3 and 56+/-7. Blood samples and urinalysis for safety analyses will be drawn during screening and on days 0, 1, 3, 7 and 28+/-3. Blood samples for Pharmacokinetic analysis will be drawn on days 0, 1, 2, 3, 7, 14+/-1, 28+/-3 and 56+/-7. Blood samples for human anti-human antibody detection will be drawn on days 0, 14+/-1 and 56+/-7.