Measuring Single-Cell Aging with an Imaging-based Biomarker of Chromatin and Epigenetic Aging

We developed imaging-based chromatin and epigenetic age image, a novel technique designed to quantify aging and rejuvenation at single cell resolution. DNA methylation clocks estimate biological age, but depend on linear regression, need large cohorts, and destroy samples, making them costly and unsuitable for large-scale or longitudinal studies. To begin, transfer the frozen organs and tissues to a pre-chilled mortar placed over dry ice.

Pour liquid nitrogen over the frozen tissue and grind it thoroughly using a pre-chilled pestle until a uniformly-fine powder is obtained. Using a pre-chilled metal spatula, aliquot the ground tissue into multiple tubes. After extracting the nuclei, mix them with trypan blue in an equal ratio in a separate tube.