Commonly, an unlabeled primary antibody binds to the protein of interest.
The Scientist (2000)
Whether lost, damaged or simply unlabeled, the process of identifying the people in old photos can be tedious.
2019, 'The Computer Scientist Who Wants To Put a Name to Every Face in Civil War Photographs',Smithsonianhttps://www.smithsonianmag.com/innovation/computer-scientist-who-wants-to-put-name-to-every-face-in-civil-war-photographs-180971754/