The EpiQuik Circulating Total Histone H3 Quantitation Kit (Colorimetric) is a complete set of optimized buffers and reagents specifically designed to quantify the levels of histone H3 proteins regardless of their modified state and can also be used to normalize the content of modified histone H3 of samples when run in parallel with the Epigentek Circulating Modified Histone H3 ELISA Kit Series.

The kit has the following features:

• The fast and efficient procedure, which can be completed in 2.5 hours.
• High sensitivity and specificity. The detection limit is as low as 2 ng / well with a dynamic range of 5-200 ng / well within the indicated amount range of plasma/serum.
• The control is conveniently included for the quantification of H3.
• The microplate strip format makes the assay flexible: manual or high throughput.
• Simple, reliable and consistent test conditions.

Context information

Histone H3, along with H2A, H2B, and H4, is involved in the structure of chromatin in eukaryotic cells. Histone H3 can undergo several different types of epigenetic modifications that influence cellular processes, such as transcription activation/inactivation, chromosome packaging, and DNA damage/repair. These modifications, which include acetylation, phosphorylation, methylation, ubiquitination, and ADP-ribosylation, occur in the N-terminal tail domains of histone H3 through the catalysis of histone-modifying enzymes, which result in remodelling of the nucleosome structure in an open conformation more accessible to transcription complexes.

In most species, histone H3 is acetylated primarily at lysine 9, 14, 18, 23, and 56; methylated in lysine 4, 9, 27, 36 and 79; and phosphorylated at ser10, ser28, Thr3 and Thr11, respectively. Recently, citrullination of H3 has also been observed and has been associated with various diseases or disease states. Therefore, the quantitative detection of various histone modifications, especially from plasma or serum samples, would provide useful information to better understand the epigenetic regulation of cellular processes and to discover new circulating biomarkers.

Principle and procedure

This kit is designed to measure total histone H3 in plasma or serum. In an assay with this kit, histone H3 proteins in the plasma/serum sample are captured in the wells of the strip coated with an anti-histone H3 antibody. Captured H3 histone can be recognized with a detection antibody followed by a colour development reagent. The proportion of histone H3 is proportional to the intensity of absorbance. The absolute amount of H3 can be quantified by comparing it to the standard control.

Materials to get started

Input materials should be plasma or serum. The amount of plasma or serum for each assay can be 10 to 40 µl with an optimal amount of 30 µl.