DTT primes MOLT-4 cells for Gal-1–induced apoptosis. (A) MOLT-4 cells were incubated with either 10 μM wt Gal-1 or 10 μM C2S-Gal-1 with or without DTT at the concentrations indicated for 8 hours, followed by analysis for PS exposure (annexin-V⁺/PI⁻) and membrane integrity loss (annexin-V⁺/PI⁺). (B) MOLT-4 cells were incubated with either 10 μM wt Gal-1 or 10 μM C2S-Gal-1 with or without DTT at the concentrations indicated for 8 hours, followed by analysis for DNA degradation by assaying for hypodiploid DNA content by flow cytometry. (C) MOLT-4 cells were incubated with either 10 μM wt Gal-1 or 10 μM C2S-Gal-1 with or without DTT at the concentrations indicated for 8 hours, followed by analysis for cellular shrinkage by flow cytometry. Error bars represent the standard deviation of duplicate samples.