DF, DF fractions, N-mers, and T-mers interact with heparin-binding proteins in a length-dependent manner. Comparison of the Kc values for DF, molecular weight fractions of DF, N-mer, and Tmer competitors of probe ClRNH32P-OdT18 binding to collagen I (A), bFGF (B), PDGF (C), and VEGF (D). All oligonucleotides were used as competitors of ClRNH32P-OdT18 (8 μmol/L) binding to collagen I (30 nmol/L, A), bFGF (50 nmol/L, B), PDGF (50 nmol/L, C), or VEGF (150 nmol/L, D) as described under “Methods.” The value of Kc for ClRNH32P-OdT18 was determined by the Cheng-Prusoff equation.18