Writing to the Genome Without Cutting

The first generation of genome editing was a pair of scissors: precise about where it cut, indifferent to what the cell did next. The repair was the gamble.

Base editors changed the verb. Rather than cutting, they chemically convert one letter of DNA into another, sidestepping the double-strand break entirely.

Prime editing goes further, using a guided reverse transcriptase to write new sequence directly — a search-and-replace for the genome.

The frontier now is delivery: getting these molecular machines into the right cells, in the right numbers, without the immune system noticing.