Credit: STEPHAN WIMMI/ ALEXANDER BALINOVIC
SINGLE-PARTICLE TRACKING PHOTOACTIVATED LOCALIZATION MICROSCOPY (SPTPALM) IS A TECHNIQUE TO VISUALIZE THE MOVEMENT OF INDIVIDUAL PROTEINS. WHILE SOME OF THE SHUTTLE COMPONENTS OF THE INJECTISOME ARE BOUND TO THE NEEDLES (WHITE, FIRMLY BOUND DOTS ON THE OUTSIDE OF THE BACTERIUM), OTHER SHUTTLE PROTEINS COMB THROUGH THE BACTERIUM (RED AND BLUE SHADING). IF THEY ENCOUNTER AN EFFECTOR, THEY BIND TO IT, WHICH CAN BE RECOGNIZED BY THE FACT THAT THEY SLOW DOWN, AND DELIVER IT TO THE NEEDLES, FROM WHERE A NEW SHUTTLE PROTEIN SETS OFF ON ITS SEARCH.