By incorporating on-chip multiplication gain, the electron multiplying CCD achieves, in an all solid-state sensor, the single-photon detection sensitivity typical of intensified or electron-bombarded CCDs at much lower cost and without compromising the quantum efficiency and resolution characteristics of the conventional CCD structure.
Objective: UPlanSApo 100x oil/1.40 | Exposure: 250 ms |
Microscope: Olympus DSU/IX81 | Gain: 3 |
Camera: Hamamatsu ImagEM | Interval: 500 ms |
The globular protein tubulin resides in the cytoplasm of the cell building and destroying microtubules, the part of the cytoskeleton that provides shape and structure to the cell. The polar arrangement of tubulin along the microtubule gives rise to its infrastructure where the beta-tubulin units bond with GTP (guanosine triphosphate) and hydrolyze it into GDP (guanosine diphosphate), therefore altering the structural integrity of the microtubule. The alpha end is chemically unable to hydrolyze GTP and so is more structurally sound. Both ends are essential to building and tearing down microtubules to change and maintain the structure of the cell. The digital video above illustrates the tracking of microtubule +TIPs (plus end tracking proteins) in human cervical carcinoma (HeLa line) epithelial cells labeled with a chimera of EB3 fused to mEGFP.