Figure 1. Hydroxymethylated DNA IP results obtained with our hMeDIP kit (Cat. No. AF-104-0016)
Hydroxymethylated DNA IP (hMeDIP) assays were performed using the Diagenode hMeDIP kit. This kit includes: the monoclonal antibody against 5-hydroxymethylcytosine (Cat. No. MAb-633HMC-050), 5-hmC, 5-mC & cytosine DNA standards & Rat IgG (Cat. No. AF-105-0025). The DNA was prepared with the GenDNA module and sonicated with our Bioruptor® (UCD-200/300 series) to obtain DNA fragments of 300-500 bp. 1 μg of mouse ES cells DNA was spiked with 0.025 ng of each DNA standard. The IP’d material has been analysed by qPCR using the primer pairs specific to the control sequences. The obtained results are as follows: - hMeDIP on unmethylated control • with Rat IgG as negative control (0.06%, almost no recovery) • with 5-hmC antibody (0.61%, almost no recovery) - hMeDIP on methylated control • with Rat IgG as negative control (0.03%, almost no recovery) • with 5-hmC antibody (0.62%, almost no recovery) - hMeDIP on hydroxymethylated control • with Rat IgG as negative control (0.04%, almost no recovery) • with 5-hmC (97.60% recovery, almost full recovery) These results clearly demonstrate the high specificity and efficiency of the 5-hydroxymethylcytosine monoclonal antibody.
Figure 2. Determination of the 5-hmC rat monoclonal antibody titer
To determine the titer, an ELISA was performed using a serial dilution of the Diagenode monoclonal antibody directed against 5-hmC (Cat No. MAb-633HMC-050, MAb-633HMC-100) in antigen coated wells. The antigen used was a 5-hmC base coupled to KHL. By plotting the absorbance against the antibody dilution, the titer of the antibody was estimated to be 1:25,000.
Figure 3. Dot blot analysis of the Diagenode 5-hmC and 5-mC monoclonal antibodies with the C, mC and hmC PCR controls
Figure 3A: Approximately 200 ng, equivalent 10 pmol of C-bases, of the hmC (1), mC (2) and C (3) PCR controls from the Diagenode “5-hmC, 5-mC & cytosine DNA Standard Pack” (Cat. No. AF-101-0002) were spotted on a membrane (Amersham Hybond-N+). The membrane was incubated with 5-hydroxymethylcytosine rat monoclonal antibody (dilution 1:500 ; 4 μg/ml final concentration), followed by an HRP conjugated anti-rat secondary antibody. The membrane was exposed during 30 seconds. Figure 3B: Incubation of the same membrane with the 5-methylcytosine mouse monoclonal antibody (Cat. No. MAb-335MEC-100/500) (dilution 1:250). Note that the membrane was not stripped after the 5-hmC incubation. The left spot represents the remaining hmC signal. This result confirms that an equal amount of mC bases was spotted at position 2.
Figure 4. Dot blot analysis of the Diagenode 5-hmC rat monoclonal antibody with the C, mC and hmC PCR controls
200 to 2 ng (equivalent of 10 to 0.1 pmol of C-base) of the hmC (1), mC (2) and C (3) PCR controls from the Diagenode « 5-hmC, 5-mC & cytosine DNA Standard Pack” (Cat. No. AF-101-0020) were spotted on a membrane (Amersham Hybond-N+). The membrane was incubated with 4 μg/ml (dilution 1:500) of the 5-hydroxymethylcytosine rat monoclonal antibody, followed by an HRP conjugated anti-rat secondary antibody. The membrane was exposed for 30 seconds.