These guidelines apply to all surgical procedures performed on rodents at the NIH in which the animals are expected to recover from anesthesia.
Survival surgery on rodents should be performed using sterile instruments, surgical gloves, masks and aseptic procedures, to reduce microbial contamination of exposed tissues to the lowest practical level. Minor surgical procedures such as wound suturing and peripheral vessel cannulation should be performed in accordance with standard veterinary practices.
A helpful site describing aseptic technique is: http://oacu.od.nih.gov/ARAC/documents/Rodent_Surgery.pdf .