The average adult human body is composed of trillions of cells. Now imagine the complexities involved in trying to study the interworkings of these microscopic cells and determine what makes one part of a cell different from another. As Ars Technica reported earlier this week, scientists trying to accomplish this task face a number of challenges – but a team of researchers have developed a technique called magnetogenetics that could provide “a new way of seeing how different biochemical pathways behave when they are activated at a specific site within the cell.” John Timmer writes:
First, they created small, magnetic nanoparticles (a bit under 500nm across) coated with a chemical that is easy to link proteins to. By linking it to a fluorescent molecule, they showed that, with a small magnetic tip, they could maneuver it around inside cells with high efficiency. The particle would take a while to work its way through the cellular environment, however.
To actually manipulate the cell, the authors coated the particles with an activated form of a protein. Normally, the protein is used to organize movement by the cell. It does this by creating structures based on actin, a protein that polymerizes into long fibers that form part of the cell’s skeleton.
The stunning photo, which looks a bit like a plant form from a Dr. Seuss book, depicts the actin fibers of a nerve cell’s growing axon, which are shown in red.
Photo by National Institutes of Health