How does CRISPR-Cas9 technology specifically improve the efficiency of gene editing in organisms?

CRISPR‑Cas9 works by letting a small RNA guide the Cas9 enzyme to a precise DNA sequence, so the cut is made exactly where you want. Because the guide RNA matches only that target, the enzyme rarely cuts elsewhere, which reduces off‑target damage that slows down or complicates editing. The cut creates a double‑strand break that the cell repairs, and scientists can add a new DNA piece that the cell incorporates, giving a clean, efficient replacement. This precision means fewer cells need to be screened to find the correct edit, speeding up experiments. For example, in mice, researchers used CRISPR‑Cas9 to insert a human gene into a single spot in the embryo, producing a viable animal in a single generation instead of years of breeding.