Localizing transcription factors on chromatin by immunofluorescence

Methods. 2002 Jan;26(1):3-9. doi: 10.1016/S1046-2023(02)00002-6.


This article contains a detailed protocol for localizing transcription factors on Drosophila melanogaster polytene chromosomes by immunofluorescence. The large polytene chromosomes from third-instar larval salivary gland cells allow mapping of chromosome-associated proteins at high resolution. Thus, this method has been used to investigate how broadly transcription factors function and to identify and characterize cis-acting protein domains, trans-acting proteins, and trans-acting DNA elements that are necessary for chromosomal association of transcription factors. The ability to directly visualize transcription factors bound to chromosomes during a transcriptionally active stage of the cell cycle has greatly enhanced our understanding of how transcription factors function in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chromatin / metabolism*
  • Chromosomes
  • Drosophila melanogaster / genetics*
  • Fluorescent Antibody Technique / methods*
  • Microscopy, Phase-Contrast
  • Transcription Factors / metabolism*


  • Chromatin
  • Transcription Factors