Aseptic technique describes surgical and laboratory methods designed to prevent microorganisms from contaminating a biological tissue, cell culture, or patient. There are no set standards for aseptic technique, but the goal is the same whether in surgery or working with cells and tissues in a biology lab - keeping the subjects free of contaminating bacteria, viruses and fungi.
Aseptic technique is necessary in a laboratory because cell and tissue samples have been isolated from the body's immune system. Tissues and growth media provide ideal places for microorganisms to grow if they are given a chance. In surgery, the patient's first line of defense against infection - the skin - has been compromised. Non-sterile surgical equipment or operating rooms will almost invariably lead to infection in the patient.