Invention:
High spatial resolution and detection of sub-cellular physiology (like respiration) is achieved using a near-field imaging surface that can be manipulated mechanically inside living biological matter. This new near-field probe is photon efficient, unlike most near-field scanning probes, and is a true imaging probe, not a point source or point collector. The mechanical structure of the imaging tip allows navigation of the probe through biological matter, including inside cells. The resolution promises to be comparable to early SEM studies, but with the ability to image dynamically in living tissue. If the information gained from SEM studies is like a snapshot, information gained from the work proposed here is like a video.
Background:
Imaging biological particles with a scanning electron microscope (SEM) has provided biologists with a wealth of structural information, but the sample cannot be examined in-vivo, and is damaged with the technique. Recent techniques for imaging with fluorescent protein (FP) tags have provided an abundance of new information, but there are difficulties associated with their use. For example, the relatively large mass (-28kDa), toxicity and limitation to a single, genetically encoded function are primary issues. In addition, even efficient FP tags only emit a small number of photons before photo-bleaching, which means that the ability to monitor samples for long periods is limited, even when sensitive detectors are used. Therefore, dynamic changes of organelles, like mitochondria, are difficult to observe with FP technology. Many variations (FRAP, FCS, FRET, FLIP, etc.) have been developed to overcome some limitations of FP technology, but they introduce their own particular difficulties.
Advantages:
- Dynamic nanometric label-free imaging of subcellular structural and functional changes that occur in response to stimuli including drugs, viruses, cancers and aging effects
- High spatial resolution and detection of sub-cellular physiology (like respiration)
- Subcellular micro/nano surgery enabled by efficient imaging and evanescent optical trapping
- Mapping of energy distributions within a cell and changes in those distributions in response to various stimuli
Status: The inventor has started investigations of biological particles, organelles, and subcellular matter at the nanoscale in new ways that include label-free imaging (no fluorescent markers), cellular micro/nano surgery, and imaging of dynamic cellular structural changes.
