Epigenetic Cell Counting
Epiontis ID offers a broad portfolio of epigenetic assays to quantify your cell type of interest.
Epiontis ID is based on cell type-specific, epigenetic biomarkers. These genomic biomarker regions are marked by the absence of CpG methylation in the respective cell types of interest, while all other cell types show complete methylation. Only demethylated biomarker regions will react with bisulfite, a chemical used in the assay. Real time PCR is then employed to quantify the number of demethylated biomarker regions, and thus the precise number of the cell type of interest, in a wide range of sample matrices including whole blood, PBMCs, tissue or in isolated genomic DNA.
Cell counting principle
The following illustrates an example of how to detect T cells in a blood sample with an Epiontis I.D. immune monitoring assay: In T cells, the CD3 gene region is epigenetically active (yellow), whereas in all other cell types, this region is epigenetically inactive (blue). In each T cell, two epigenetically active (yellow) alleles are present and will be amplified by PCR. Non-T cells are not detected. The number of epigenetically active CD3 gene copies directly translates into the number of T cells in the sample. The parallel measurement of epigenetic reference systems, e.g. the housekeeping gene GAPDH, allows for total cell number determination.
The figure illustrates the use of epigenetic markers to determine cell counts of a specific cell type. For further technical details, please refer to Sehouli et al., Epigenetics 2010.
Comparison to flow cytometry
The comparison of flow cytometric samples with samples measured with the epigenetic technology of Epiontis show good correlation.