1. A plasmid vector used in molecular biology that combines features of cosmids and plasmids, capable of carrying large DNA inserts of 30–45 kilobases for cloning and genetic engineering.
Usage: technical; molecular biology

Examples

• Researchers used a cosmid to clone the large gene segment.
• The cosmid vector allowed scientists to insert DNA fragments much larger than traditional plasmids could accommodate.
• Cosmids were instrumental in early genome mapping projects.
• The laboratory prepared cosmid libraries to study complex genetic regions.
• By using cosmids, the team could analyze genes spanning tens of thousands of base pairs.