Skip to content
Login Register

#ChIP assay

3 public questions tagged with this topic.

DNA-Protein Interaction analysis

Which protein showed constitutive binding to the break site in ChIP?

Time-resolved ChIP after inducing chromosomal break distinguishes persistent versus dynamic repair factor recruitment. Some proteins peak transiently then dissociate, others spread outward. Constitutive binding indicates stable occupancy at break site across all examined intervals without significant decline. In described experimental dataset, enrichment profiles show Rep3 maintaining high occupancy at break site from initial time point through later points, suggesting role as scaffold or structural maintenance component anchoring repair complex. This contrasts with Rep1 transient recruitment and Rep2 spreading phenotype, establishing Rep3 as constitutive binder at break.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details
DNA-Protein Interaction analysis

In a ChIP assay, if Rep2 binds DNA at the break site and 1 kb away after 30 mins, it suggests:

Chromatin Immunoprecipitation time course following double-strand break induction provides insight into protein recruitment dynamics. Exclusive detection at break site initially reflects damage recognition. Subsequent detection both at break and one kilobase away after thirty minutes demonstrates progressive propagation along flanking chromatin. Such pattern indicates spreading of binding activity, oligomerization along DNA, recruitment of secondary repair factors or extension of chromatin modifications like gamma-H2AX domain. Transient binding would show disappearance, replication would involve synthesis markers. Spreading behavior typifies checkpoint mediators coordinating extensive chromatin regions for homologous recombination repair.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details
DNA-Protein Interaction analysis

Which method allows immunoprecipitation of protein-DNA complexes?

Chromatin Immunoprecipitation is definitive technique for immunoprecipitating protein-DNA complexes from living cells. Cells are crosslinked with formaldehyde to covalently stabilize transient protein-DNA contacts. Chromatin is sheared by sonication or micrococcal nuclease to fragments of 200-500 base pairs, incubated with antibody specific to transcription factor or histone modification, captured on protein A or G beads. After extensive washing, crosslinks are reversed, proteins digested, DNA purified for PCR or sequencing. This in vivo approach directly identifies genomic loci occupied, unlike in vitro EMSA or Western blot.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details