Integrative Graduate
Education and
Research Traineeship

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Using Quantum Dot Blinking on Cell Surfaces

Quantum Dots

Projects:

IGERT: Physical & Biomolecular Foundations for Designing...

Institution:

Johns Hopkins University

Primary Strategic Goal:

Discovery: Foster research that will advance the frontiers of knowledge, emphasizing areas of greatest opportunity and potential benefit and establishing the Nation as a global leader in fundamental transformational science and engineering.

Secondary Strategic Goal:

Learning: Build the Nation's research capability through critical investments in advanced instrumentation, facilities, cyber infrastructure, and experimental tools.

Achievement/Results

Traditionally, one way to look at features on a cell is through attaching a fluorescent particle to a protein on a cells surface, and tracking the position and movement of that particle. However, while this can give a large-scale view of presence or absence of some protein, the limits of resolution of a microscope often prevent us from learning many useful things, such as how evenly distributed a protein is, or how many particles are in a given spot. Recently quantum dots have become a commonly used imaging particle due to their brightness and long lifetimes. However, one often overlooked feature of Quantum Dot behavior is their blinking; their irregular switching from “on” states to off states and back. IGERT fellow Adam Shelley in the Edidin lab performs research to exploit that blinking behavior. Through careful analysis of changes in blinking rates we can determine how the dots are arranged and how they interact with each other. Through applying this analysis to Quantum Dot labeled cells, we can extract new information on how cell surfaces are organized.

Address Goals

IGERT has been critical to my work thus far. Adams work on Quantum Dots on cell surfaces has been fully interdisciplinary from the start: the investigation of relevant biological systems with a novel tool that requires a firm grounding in the physics of the situation to properly understand and analyze.

Without IGERT backing and encouragement, it would not have been possible to work with biology faculty to the extent he has as a physics student, or to have recieved the necessary background work with cell cultures and fluorescent microscopy, which makes this Quantum Dot project possible at all. Instead of a standard physics grant which could have, at best, left me investigating Quantum Dot behavior with no potential applications, I am now working full-time on a project that may greatly change our understanding of T-cell behavior, through applying what I am learning about the physics of Quantum Dots.