Fig 1: DNA purification reagents vary in their ability to recover low amounts of DNA from de-crosslinked chromatin. a Recovered DNA amount by different DNA purification reagents from de-crosslinked chromatin. De-crosslinked chromatin estimated to include 1 ng range DNA in ChIP elution buffer was purified following the manufacturer’s instructions. The data were generated from triplicate DNA samples derived from three independent preparations. Zy, ChIP DNA Clean & Concentrator™ (Zymo Research); Pr, Wizard® SV Gel and PCR Clean-Up System (Promega); Th, GeneJET PCR Purification Kit (Thermo Fisher Scientific); In, PureLink® PCR Purification Kit (Invitrogen); Ne, Monarch® PCR & DNA Cleanup Kit (New England Biolabs); Am, Chromatin IP DNA Purification Kit (Active Motif); Qp, QIAquick PCR Purification Kit (Qiagen); Qm, MinElute PCR Purification Kit (Qiagen); Ba, Agencourt AMPure XP kit (Beckman, chromatin to beads ratio from 1:1.25 to 1:2); Br, RNAClean™ XP kit (Beckman, chromatin to beads ratio from 1:1.25 to 1:2); PC, phenol/chloroform extraction. b Interference of PCR amplification by purified eluent of purification reagents. 9 µL eluent was mixed with 1 µL 166 bp of Drosophila probe DNA (0.0001 ng), and the resulting mixture was used as the template in 20 µl of real-time PCR reaction. The Ct value for Drosophila probe DNA from TE buffer was set as 100%. The experiment was repeated 3 times using de-crosslinked chromatin estimated to include 1 ng of DNA. c Size profiles of DNA purified by different reagents. The DNAs purified from de-crosslinked chromatin estimated to include 50 ng range DNA was analyzed by AATI Fragment Analyzer. DNA size (bp) is shown