Figure 3. Affinity purification of histone tails.

Histone tails can be used as baits for affinity purification, enabling the identification of proteins binding to particular histone modifications. The unmodified or modified peptides were immobilized on beads and treated with nuclear extracts from metabolically labeled cells. The beads were then washed to remove nonspecifically associated proteins and pooled. Associated proteins were eluted and mixed in a 1:1 ratio, resolved with SDS-PAGE gel, then the entire lane was in-gel digested and analyzed by LC–MS/MS.

LC–MS: Liquid chromotography–mass spectrometry; MS: Mass spectrometry.