Figure 1.

Three-dimensional view of scan 35 from a multiwavelength sedimentation velocity experiment of BSA (top) and scan 16 from a mixture of DNA fragments (bottom) measured between 240 and 310 nm.The meniscus is clearly visible at ~6.0 cm. For BSA, an absorbance maximum is visible at 278 nm from tyrosine and tryptophan residues, and below 250 nm absorbance from the peptide backbone increases for BSA, while a 258 nm peak typical for DNA results in a pronounced difference between the two biological macromolecules.