Brenda Maribel Corado was walking down a street in Guatamala when two women beat her and snatched away her three-week-old baby girl. Two months later, baby Angela turned up at a church. When Angela’s DNA was tested, Corado and her husband matched with 99.9% accuracy, and the baby girl was reunited with her parents.

Unfortunately, many stories of missing persons don’t end as well as Angela’s. Every year, hundreds of thousands of children are sold into modern-day slavery, often to be sexually exploited, at too young an age to know who they are or where they’re from, according to Jose Lorente of the University of Granada Genetic Identification Laboratory in Spain. Human trafficking—internationally defined as forcible coercion or selling of people—has become a $32 billion international industry.

Read more of my feature at BioTechniques.

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.