Competition between unlabeled trans-DDP-modified, cis-DDP-modified, and unmodified 34-bp fragments for binding to histone H1 bound to labeled cis-DDP-modified 34-bp fragment. Lane C contains the labeled cis-DDP-modified 34-bp fragment only; lane C1 contains the same fragment bound to histone H1, in the absence of competitor DNA. The amount (fold molar excess) of cis- and trans-competitor DNA in consecutive lanes is as follows: 1, 5, 10, 20, 50, 100, and 200; the unmodified competitor was added at 5-, 10-, 20-, 100-, and 200-fold excess.