Chromatin immunoprecipitation coupled with massively parallel DNA sequencing (ChIP-seq) is the gold standard for assaying the binding sites of chromatin-binding proteins and their modifications, such as histone tail modifications. One major limititation for this method is that it requires large amounts of starting material, therefore limiting applications in those cases where only a limited number of cells can be recovered, e.g. rare cell populations obtained directly from patients. In the last few years, great efforts have been made to develop new ChIP-seq protocols to overcome this limitation. In my lab, they have developed a method called carrier ChIP-seq (cChIP-seq). The method is based on the use of a DNA-free carrier to enhance recovery of DNA after IP. Using cChIP-seq they have been able to perform ChIP-seq on 10,000 cells for several histone tail modifications. I tested a series of modifications on the cChIP-seq protocol. The goal of my project was to develop a protocol that can be performed in one day. Currently the cChIP-seq protocol takes 3 days to be complete. This is mainly due to two overnight incubations. The first one is the immunoprecipitation, so I performed multiple trials to identity the minimum time sufficient for immunoprecitating the chromatin. The second overnight incubation is to reverse crosslink immuneprecipitated chromatin. I tested a version of the cChIP-seq protocol for native chromatin, meaning the DNA is not crosslinked. By optimizing and combining these two modifications I was able to shorten the cChIP-seq to a single day. Through my project I contributed to a larger project with the goal of scaling down the number of cells used for ChIP-seq.