The first step of a ChIP assay is the cross-linking in order to fix the cells. Cross-linking is typically achieved by using formaldehyde which forms reversible DNA-protein links. Formaldehyde rapidly permeates the cell membranes and enables a fast cross-linking of closely associated proteins in intact cells. However, formaldehyde is usually not effective to cross-link proteins that are not directly bound to the DNA. For example, chromatin interactions with inducible transcription factors or with cofactors that interact with DNA through protein-protein interactions are not well preserve with formaldehyde. So, for higher order and/or dynamic interactions, other cross-linkers should be considered for efficient protein-protein stabilization such as the Diagenode ChIP cross-link Gold. This reagent is to use in combination with formaldehyde. The protocol involves a sequential fixation. A first protein-protein fixation by the ChIP cross-link Gold followed by protein-DNA fixation by formaldehyde.
Format: supplied as a 250 x concentrated solution
Shipping conditions: shipped at -20°C
Storage conditions: Store at -20°C; for long storage, store at -80°C. Avoid multiple freeze-thaw cycles.