Pinpoints subtle but critical changes in cells to reveal vital health information
Knowing the exact number of molecules located at specific junctures in cells can be a critical measure of health as well as disease. For example, abnormally high numbers of growth factor receptors on cells can be an indication of cancerous and precancerous states; specific proteins located at the junction where neurons connect in the brain may affect brain function as they accumulate or disperse.
Until recently, researchers have had to use either very expensive microscope hardware, or highly complex — and often imprecise — microscopy software, to see individual, fluorescently-labeled molecules in tightly bunched groups in cells. Now, a simplified method known as qPAINT uses the blinking pattern of the light that marks each molecule, to find, count and study individual molecules that are just a few nanometers apart — all using the standard microscopes already found in laboratories.
“qPAINT allows identification of each point of light coming from a labeled molecule without the need for complex and sometimes inexactmicroscopy calculations,” explains Behrouz Shabestari, Ph.D., Director of the NIBIB program in Optical Imaging and Spectroscopy. “The method overcomes the problem that occurs when trying to visualize molecular structures that are in very close proximity: light diffuses as it leaves the spot where it originates. This masks exactly how many points of light—each representing a single molecule—are actually creating the light.”