To determine the titer of the antibody, an ELISA was performed using a serial dilution of the Bioss antibody directed against H3K27me2 (cat. No. bs-53109R). The antigen used was a peptide containing the histone modification of interest. By plotting the absorbance against the antibody dilution, the titer of the antibody was estimated to be 1:480,000.


A Dot Blot analysis was performed to test the cross-reactivity of the Bioss antibody against H3K27me2 (cat. No. bs-53109R) with peptides containing other modifications of histone H3 and H4 and the unmodified sequence. One hundred to 0.2 pmol of the peptide containing the respective histone modification were spotted on a membrane. The antibody was used at a dilution of 1:50,000. The figure shows a high specificity of the antibody for the modification of interest.


Histone extracts (15 μg) from HeLa cells were analyzed by Western blot using the Bioss antibody against H3K27me2 (cat. No. bs-53109R) diluted 1:1,000 in TBS-Tween containing 5% skimmed milk. The position of the protein of interest is indicated on the right; the marker (in kDa) is shown on the left.


HeLa cells were stained with the Bioss antibody against H3K27me2 (cat. No. bs-53109R) and with DAPI. Cells were fixed with 4% formaldehyde for 10’ and blocked with PBS/TX-100 containing 5% normal goat serum and 1% BSA. The cells were immunofluorescently labeled with the H3K27me2 antibody (left) diluted 1:500 in blocking solution followed by an anti-rabbit antibody conjugated to Alexa488. The middle panel shows staining of the nuclei with DAPI. A merge of the two stainings is shown on the right.