Conceiving a child is an emotionally painful and exhausting process for those who struggle with infertility, and the worries don't stop with achieving pregnancy: all expectant parents hope for healthy babies. For individuals with known risks who are undergoing in vitro fertilization (IVF), preimplantation genetic diagnosis—in which clinicians remove a cell from an early embryo and screen it for genetic disorders—is a way to select an unaffected embryo, though current techniques analyze only one or a few sites in the genome. The cells of an early embryo are few and precious, so clinicians are keen to learn as much as possible from the limited numbers of cells.
That's one big problem that single-cell whole-genome sequencing methods are promising to resolve in early embryonic development and other fields. Thanks to improved approaches for isolating individual cells and for amplifying and sequencing their tiny complement of DNA or RNA, scientists can scan entire genomes or transcriptomes rather than a few targeted sites, and at higher resolution than was previously possible.
See the rest of my story, a feature on Nature Methods' Method of the Year.