High-tech laboratory tools are often updated publicly as their analytical capabilities expand. In the September issue of the Journal of Molecular Diagnostics, National Institues of Health grantees report they have developed a second generation "lab on a silicon chip" called the MitoChip v2.0 that, for the first time, rapidly and reliably sequences all mitochondrial DNA. Mitochondria, the energy-producing organelles that power our cells, are unique because they are equipped with their own genetic instructions distinct from the DNA stored in the cell nucleus.
The authors say their full-sequence chip will be a key tool in accelerating research on mitochondrial DNA, a growing area of scientific interest. This interest stems from data that suggest natural sequence variations and/or mutations in each person’s mitochondrial DNA could be biologically informative in fields as diverse as cancer diagnostics, gerontology, and criminal forensics.
According to Joseph Califano, a scientist at Johns Hopkins University School of Medicine in Baltimore and senior author on the paper, the MitoChip v2.0 showed better sensitivity than its predecessor to sequence variations in head and neck cancer samples. The v2.0 also detected nearly three dozen variations in the non-coding D-loop, long considered to be a sequencing no-man’s land and which the original MitoChip did not include.
"At this point, we don’t foresee a MitoChip v3.0," says Califano, whose research was supported by the NIH’s National Institute of Dental and Craniofacial Research. "The v2.0 is a very good tool in that we’ve also arrayed 500 of the most common haplotypes—or grouped patterns of known DNA variations—banked in the mitochondrial public database."