X-Ray Assisted Electron Microscopy Staining Procedure

Background

Researchers in the Princeton Neuroscience Institute, Princeton University have developed an X-ray assisted staining procedure, which allows for tight control over the staining process and can serve as a very important and unique entry point for staining quality control while the protocol is conducted. This could not only be very useful for any basic research lab that uses electron microscopy for example to study the ultra-structure of brain tissue, but more importantly, it could finally enable an industrial-scale, fully automated and tightly controlled electron microscopy staining pipeline, which will allow for a real- time, continuous check on the quality and homogeneity of the staining without damaging or destroying the sample. This could also  be very useful for potential electron microscopy-based high-throughput drug screening assays in the pharmaceutical industry

Technology

Typical electron microscopy staining protocols for biological samples consist of several steps in which a sample (e.g. a piece of brain tissue) is immersed in various heavy metal solutions. These heavy metals react with and bind to lipids, proteins or DNA and thereby stain these macromolecules and cellular structures. In thick samples however, it is difficult to establish homogeneous staining through-out the sample, mainly because of different diffusion kinetics in different regions of the sample. So far, the quality and homogeneity of the staining could only be assessed after the whole staining protocol has been conducted, including a final embedding step in an Epoxy resin. A typical staining protocol takes several days until the usual assessment by electron microscopy is possible. That assessment involves cutting the sample into ultrathin sections that can be viewed in an electron microscope, which is a destructive and very time-consuming process. 

Benefits

•       Non-destructive, real-time quality control

•       Uses commercially available equipment

•       Live monitoring of staining quality and heavy metal diffusion

Applications

•       Electron microscopy staining for biological samples

•       High-throughput drug screening assays

•       Industrial-scale, fully automated and tightly controlled electron microscopy staining pipeline

Additional info

Issued patent. Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity.