Randomly amplified polymorphic DNA

A DNA fingerprinting technique, usually abbreviated to RAPD, that amplifies randomly selected genomic sequences by PCR under low-stringency conditions using short arbitrary primers. Because no prior sequence knowledge is needed, it can determine taxonomic identity, study genetic diversity, generate probes, and analyze mixed genome samples across organisms from crops to microbes. In food science it has been applied to authenticating varieties, tracing contamination sources, and characterizing starter cultures. Its sensitivity to reaction conditions demands strict standardization for reproducibility, and it has largely been complemented by more robust marker systems, but it remains a fast, inexpensive diversity screen.