DNA and forensics. DNA isolated from sperm obtained during the examination of a rape victim was amplified by PCR, then compared with DNA from the victim and three potential suspects—the victim’s husband and two additional individuals—using gel electrophoresis and autoradiography. Sperm DNA matched the pattern of Suspect 1, but not that of Suspect 2 or the victim’s husband. Sizing marker and K562 lanes refer to control DNA samples.

[Martin Shields/Science Source.]