Fig. 1
From: Titration-based normalization of antibody amount improves consistency of ChIP-seq experiments
Direct measurement of DNA content in chromatin input enables to quantify the amounts of usable input from individual samples. A The DNA content directly measured in chromatin input (DNAchrom) is correlated with the amount of purified DNA. Chromatin input was prepared from fixed K562 cells. DNA amount was directly measured in chromatin input ranging 0.3 – 20 µg by the Qubit dsDNA high sensitivity assay and compared with the amount of purified DNA. The Qubit assay was performed by incubating 2 µl of chromatin input with 198 µl of Qubit reagent. The data was presented as mean ± SD from 2 experiments performed in triplicates. Coefficient of determination (R2) was calculated by the linear regression model. B Correlation between DNAchrom and the amount of chromatin input determined by purified DNA in various sample types. Chromatin input was prepared from cell lines (n = 78), solid tissues (n = 534), and samples derived from peripheral blood (n = 54). DNAchrom was measured from 0.5—1% of chromatin input in individual ChIP reactions and compared with the amount of chromatin input determined by purified DNA