Bicoid, counter-purified agians D. virilis protein (Li et al. 2008)
Sequenced DNA Library
Chromatin was isolated by CsCl gradient ultracentrifugation, fragmented and immunoprecipitated with affnity-purified antibody Libraries were prepared according to Illumina's instructions accompanying the DNA Sample Kit (Part# 0801-0303). Briefly DNA fragments were converted to phosphorylated blunt ends using T4 DNA polymerase, Klenow DNA polymerase, and T4 polymerase kinase, a 3' A base overhang was added using Klenow DNA polymerase exo- (3' to 5' exo minus), and Illumina adapters were ligated to the fragments. We carried out the PCR step for enrichment of adapter-modified DNA prior to the library size selection, and limited the amplification to 15 cycles. After the amplification step, we size-selected DNA fragments of 150-250 bp.