Pronuclear transfer, in the context of human reproductive technology, is used for preventing mitochondrial diseases in offspring. Here's why - Mitochondria: These are cellular organelles with their own DNA (mitochondrial DNA or mtDNA) separate from nuclear DNA. Mutations in mtDNA can cause various inherited mitochondrial diseases that can affect organs like muscles, nerves, and the brain. - Pronuclear Transfer Technique: This technique involves the fertilization of an egg with sperm. Then, the pronuclei (nuclei before fusion) from both sperm and egg are removed. These pronuclei are then injected into a donor egg that has had its own pronuclei removed, but has healthy mtDNA.