Automated Microfluidic Blotless Specimen Preparation for Cryo-TEM
Overview
Transmission electron microscopy (TEM) is an important imaging tool in many physical and biological scientific fields. Because current methods for preparing the thin TEM specimens are specific to the material being analyzed and the information being sought, many different methods are used. Our method for automatically preparing TEM specimens deposits extremely small samples onto a grid, doing away with the need for a blotting step and enabling images of previously unobserved structures.
Market Opportunity
With TEM, an electron beam is transmitted through an ultra-thin specimen, interacting with the specimen to create an image. The small wavelength of the electron beam allows TEM to create images of significantly higher resolution than those of traditional light microscopes. With conventional methods of TEM specimen preparation, however, the required blotting step can deform the structure of the molecule of interest. Thus, there is a need for a method of TEM specimen preparation that automatically places and controls the size of the sample droplet formed, eliminating the need for a blotting step.
Innovation and Meaningful Advantages
With our method, a sample liquid droplet is formed at the end of a capillary, and a portion of the liquid is transferred to the TEM sample grid by contact. The excess volume of the liquid droplet is then retracted by an adjacent capillary. The flow rate of injection/retraction and the growth of the drop on the capillary tip are evaluated, to tune the starting time of the retraction capillary motion. After a predetermined time interval, the retraction capillary is moved toward the drop of the sample to remove the excess volume. Once the sample is deposited and retracted, the grid is quickly plunged into liquid ethane to vitrify the sample. All of the steps are controlled by a computer, allowing accurate knowledge of microstructure at the time of freezing.
Unlike conventional specimen preparation methods, in which the blotting step can deform the structure of the molecule of interest, our method uses a very low shear rate for removal of the excess sample fluid. The acceleration of the preparation process also allows previously unobserved structures to be viewed.
Collaboration Opportunity
We are interested in exploring 1) research collaborations with leading biological imaging companies to further develop this technology; and 2) licensing opportunities with biological imaging companies.
Principal Investigator
Anubhav Tripathi, PhD
Professor of Engineering
Director of Biomedical Engineering
Brown University
Brown Tech ID #1966J
anubhav_tripathi@brown.edu
https://vivo.brown.edu/display/atripath
IP Information
2016-05-31 US9,355,813B2; Issued
2016-04-12 US9,312,095B2; Issued