Methods predating CRISPR, such as SSAPs and homologous recombination, are precise and powerful for genome editing, with SSAPs enabling the creation of billions of edited cells daily by a single person.

“Another one that dates back two decades before CRISPR is SSAPs or lambda red as it's sometimes called is a way of getting precise editing. And that's what we actually used to...around 2009 to make libraries of billions of edited cells in a day, a single person. That shows some of the power. And the other evidence of its power was that that was...the first completely recoded genome was done mostly a combination of SSAPs and recombinases, which is also very precise.”