Comparison between the 5fC-antibody immunoprecipitation and chemical pulldown method. (a) For the 5fC DNA immunoprecipitation we used 1 pg of 5fC-103mer and 10 pg C-103mer in the presence of 5 µg salmon sperm DNA. The immunoprecipitation resulted in an enrichment of 1.6-fold of the 5fC-103mer over the C-103mer. Error bars represent the standard error of the mean. (b) Conditions for the biotinylation reaction of a 9-mer containing a single 5fC. The oligonucleotide was incubated at room temperature with an ARP in the presence of anisidine at pH 5 for 24 h and resulted in the formation of a single product. (c) Pulldown of 1 pg 5fC-biotin-103mer in the presence of 10 pg C-103mer and 5 µg salmon sperm DNA using streptavidin-coated magnetic beads resulted in an enrichment of the biotinylated DNA of around 1,000-fold. Error bars represent the standard error of the mean.