Single-chain antibodies neutralize activity and bind nonoverlapping epitopes of botulinum A neurotoxin. Two phage display epitope libraries were constructed from the 1.3 kb of binding domain cDNA. The minimal epitopes selected against the single-chain Fv-Fc antibodies correspond to conformational epitopes with amino acid residues 1115 to 1223 (S25), 1131 to 1264 (3D12), and 889 to 1294 (C25)

Acute lymphoblastic leukemia (ALL), the most common cancer compartment (CD34 + Lin − ) that in normal hematopoiesis con-

These results contrast with the rapid clearance of donor WBCs observed in humans and dogs. The immunologic basis for this discrepancy remains unclear. Caution should be exercised in any extrapolation to humans of conclusions drawn from results in transfused mice.