Cell Imaging: An All-Access Pass

Today’s cell imaging devices provide a level of access to the cellular world that was unthinkable until fairly recently. Previously, biologists were restricted to a few dyes that allowed them to distinguish a few subcellular structures. Now, the convergence of advances in multiple fields is providing researchers increased resolution and detail in viewing the molecular and cellular worlds.

Innovation and improvement, in both devices and reagents, brought about this new age of imaging. Chemists developed sophisticated fluorescent dyes specific and sensitive enough to facilitate imaging of proteins or certain cell structures. Physicists and engineers merged the confocal microscope with newer technologies to enable resolution high enough to observe live cells without disturbing them. One of these technologies is the Nipkow dual-disk technology. Spotted with pinholes, the disks create beams of light for rapid scanning of the entire specimen, creating a real-time image. The speed enables the camera to capture the swift moves of molecules in the cells without compromising resolution.

Cameras, also known as charge-coupled devices (CCDs), are sensors that receive the light of the cells, convert the electron signals into voltage, translate that voltage into an image, and then feed the image into a computer for storage. Many researchers prefer cooled CCDs because are much more sensitive and tend to generate images with less noise. Cooled CCDs are especially important if you’re working with faint or extremely detailed images, both of which take much longer to scan, causing more noise to enter the image.

Adding automation was the final piece that cleared the path to high content screening. With this capability, researchers graduated from just observing the presence and/or structures of molecules and cells to capturing cells’ reactions to external perturbations, such as the binding of signaling molecules, antibodies, inhibitory RNA molecules, small molecule drug candidates, or other ligands. Automated devices can add the appropriate reagents and then immediately capture the reactions of cell after cell. Set up with robotic accessories, such as plate stackers, loaders, and barcode readers, the devices can continue hands-free operation overnight and beyond.

Be sure to take a close look at several cell imaging systems before you purchase one. Cell imaging systems differ in the colors and types of probes that can be imaged, and how many can be simultaneously detected. If you’ll be using more than one format, such as different microplates or microscope slides, be sure to check for that level of flexibility. You can also find systems that provide real-time video of your samples, which allows you to optimize focus and balance; or else the autofocus feature can do the job. And don’t forget to take a test run of the software. Be sure you feel comfortable with it and that it provides the types of analyses that you need.

Look below to get a good idea of what’s currently available in cell imaging.