Principal scientists Matt Drever (left) scrapes bacteria from an agar plate during an antibody phage experiment as principal scientist Charlie Holst watches at the Pfizer laboratory at the the University of California at San Francisco (UCSF) Mission Bay campus in San Francisco, Dec. 18, 2012.

Principal scientist Matt Drever scrapes bacteria from an agar plate during an antibody phage experiment at the Pfizer laboratory at the University of California at San Francisco (UCSF) Mission Bay campus in San Francisco, Dec. 18, 2012.

Principal scientist Charlie Holst demonstrates scanning cells on a 96-well plate to measure for levels of signaling proteins at the Pfizer laboratory at the University of California at San Francisco (UCSF) Mission Bay campus in San Francisco, Dec. 18, 2012.