Figure 4.

Deviations between measured and predicted extinction coefficients for 18 ssDNA oligomers. Closed symbols are for non-repetitive (complex) sequences, open symbols for repetitive (simple one- or two-base repeats). (a) Circles have ε₂₆₀ = 10 ODU/µmol of monomer unit (33 µg/ODU); triangles, the weighted sum of mononucleotides; squares, nearest-neighbor estimation (14). (b) Circles have ε₂₆₀ = 8.7 ODU/µmol (38 µg/ODU), and include the correction of Equation 2 for measurements (23,26) that are based on the monomer values of Warshaw (8), Warshaw and Tinoco (9) and Cantor et al. (10). (c) Percentage (A + G) was used to order the 18 DNA sequences. The vertical axis scale is the same for all panels