Have you ever wondered what creates striking images of cells and other tiny structures? Most often, the answer is microscopes. Many of us have encountered basic light microscopes in science classes, but those are just one of many types that scientists use. Check out the slideshow to see images researchers have captured using different kinds of microscopes. For even more images of the microscopic world, visit the NIGMS Image and Video Gallery.Continue reading “A Focus on Microscopes: See Eye-Catching Images”
Tag: Cellular Imaging
Students, teachers, and other curious minds can step into a scientific imaging lab with a free online interactive developed by NIGMS and Scholastic. Imaging tools help scientists unlock the mysteries of our cells and molecules. A better understanding of this tiny world can help researchers learn about the body’s normal and abnormal processes and lead to more effective, targeted treatments for illnesses.Continue reading “Explore Scientific Imaging Through a Virtual “Internship””
NIGMS and Scholastic bring you our latest issue of Pathways, which focuses on imaging tools that help scientists unlock the mysteries of our cells and molecules. A better understanding of this tiny world can help researchers learn about the body’s normal and abnormal processes and lead to more effective, targeted treatments for illnesses.
Pathways is designed for students in grades 6 through 12. This collection of free resources teaches students about basic science and its importance to health, as well as exciting research careers.Continue reading “Pathways: The Imaging Issue”
To get a look at cell components that are too small to see with a normal light microscope, scientists often use cryo-electron microscopy (cryo-EM). As the prefix cryo- means “cold” or “freezing,” cryo-EM involves rapidly freezing a cell, virus, molecular complex, or other structure to prevent water molecules from forming crystals. This preserves the sample in its natural state and keeps it still so that it can be imaged with an electron microscope, which uses beams of electrons instead of light. Some electrons are scattered by the sample, while others pass through it and through magnetic lenses to land on a detector and form an image.
Typically, samples contain many copies of the object a scientist wants to study, frozen in a range of orientations. Researchers take images of these various positions and combine them into a detailed 3D model of the structure. Electron microscopes allow us to see much smaller structures than light microscopes do because the wavelengths of electrons are much shorter than the wavelength of light. NIGMS-funded researchers are using cryo-EM to investigate a range of scientific questions.
Caught in Translation
Joachim Frank, Ph.D., a professor of biochemistry and molecular biophysics and of biological sciences at Columbia University in New York, New York, along with two other researchers, won the 2017 Nobel Prize in Chemistry for developing cryo.
Dr. Frank’s lab focuses on the process of translation, where structures called ribosomes turn genetic instructions into proteins, which are needed for many chemical reactions that support life. Recently, Dr. Frank has adopted and further developed a technique called time-resolved cryo-EM. This method captures images of short-lived states in translation that disappear too quickly (after less than a second) for standard cryo-EM to capture. The ability to fully visualize translation could help researchers identify errors in the process that lead to disease and also to develop treatments.Continue reading “Freezing a Moment in Time: Snapshots of Cryo-EM Research”
The red spray pictured here may look like fireworks erupting across the night sky on July 4th, but it’s actually a rare glimpse of tiny protein strands called microtubules sprouting and growing from one another in a lab. Microtubules are the largest of the molecules that form a cell’s skeleton. When a cell divides, microtubules help ensure that each daughter cell has a complete set of genetic information from the parent. They also help organize the cell’s interior and even act as miniature highways for certain proteins to travel along.
As their name suggests, microtubules are hollow tubes made of building blocks called tubulins. Scientists know that a protein called XMAP215 adds tubulin proteins to the ends of microtubules to make them grow, but until recently, the way that a new microtubule starts forming remained a mystery.
Sabine Petry and her colleagues at Princeton University developed a new imaging method for watching microtubules as they develop and found an important clue to the mystery. They adapted a technique called total internal reflection fluorescence (TIRF) microscopy, which lit up only a tiny sliver of a sample from frog egg (Xenopus) tissue. This allowed the scientists to focus clearly on a few of the thousands of microtubules in a normal cell. They could then see what happened when they added certain proteins to the sample.
Cells are the basis of the living world. Our cells make up the tissues and organs of our bodies. Bacteria are also cells, living sometimes alone and sometimes in groups called biofilms. We think of cells mostly as staying in one spot, quietly doing their work. But in many situations, cells move, often very quickly. For example, when you get a cut, infection-fighting cells rally to the site, ready to gobble up bacterial intruders. Then, platelet cells along with proteins from blood gather and form a clot to stop any bleeding. And finally, skin cells surrounding the wound lay down scaffolding before gliding across the cut to close the wound.
This remarkable organization and timing is evident right from the start. Cells migrate within the embryo as it develops so that body tissues and organs end up in the right places. Harmful cells use movement as well, as when cells move and spread (metastasize) from an original cancer tumor to other parts of the body. Learning how and why cells move could give scientists new ways to guide those cells or turn off or slow down the movement when needed.
Scientists studying how humans and animals form, from a single cell at conception to a complex body at birth, are particularly interested in how and when cells move. They use research organisms like the fruit fly, Drosophila, to watch movements by small populations of cells. Still, watching cells migrate inside a living fly is challenging because the tissue is too dense to see individual cell movement. But moving those cells to a dish in the lab might cause them to behave differently than they do inside the fly. To solve this problem, NIGMS-funded researcher David Bilder and colleagues at the University of California, Berkeley, came up with a way to alter fly cells so they could track how the cells behave without removing them from the fly. They engineered the cells to lay down a glowing track of proteins behind them as they moved, leaving a traceable path through the fly’s tissue. The technique, called M-TRAIL (matrix-labeling technique for real-time and inferred location), allows the researchers to see where a cell travels and how long it takes to get there.
Bilder and his team first used M-TRAIL in flies to confirm the results of past studies of Drosophila ovaries in the lab using other imaging techniques. In addition, they found that M-TRAIL could be used to study a variety of cell types. The new technique also could allow a cell’s movement to be tracked over a longer period than other imaging techniques, which become toxic to cells in just a few hours. This is important, because cells often migrate for days to reach their final destinations.
The yellow-green glow from this summer’s fireflies teased my kids across the yard. Max and Stella zigzagged the grass, occasionally jumping into the air to cup a firefly in their hands and then proudly shouting, “I got one!”
Chasing fireflies on a summer night is a childhood rite of passage for many, including Nathan Shaner who grew up in New Jersey. “It was one of my favorite things about summer,” he recalls. “I’d catch them with my hands—I’d never jar them.”
Today, Shaner studies the science of bioluminescence, which gives fireflies and many other organisms the natural ability to emit light. His goal is to make bright bioluminescent tags that he and other scientists can use to study living cells in greater detail. “There’s this very beautiful thing that evolved in nature, and we can use it to enable new discoveries,” he says.
Thousands of organisms glow as a way to communicate, spook predators, lure prey or attract mates. There are a few terrestrial examples, such as fireflies, glowworm insect larvae and foxfire fungi, and many more aquatic ones, including types of marine plankton, fish, jellyfish, shrimp, squid and sea urchins. One research team estimated nearly three quarters of sea life have bioluminescent capabilities.Continue reading “Chasing Fireflies—and Better Cellular Imaging Techniques”
Our eyes are the gateway to countless brilliant sights. However, as evidenced by the images on this page, the eye itself can be breathtakingly exquisite as well. This May, as we celebrate Healthy Vision Month with the National Eye Institute, we hope sharing the beauty hidden in your eyes will inspire you to take the necessary steps to protect your vision, prevent vision loss and make the most of the vision you have remaining.
Visit NEI to learn more about caring for your eyes.
Happy Healthy Vision Month!
This heart-shaped image shows two mouse skin cancer cells connected to each other with actin, a protein that is part of the cellular skeleton. Researchers use mouse cells like these to tease out the molecular methods that cancer uses to invade new tissues in the body. It turns out that actin plays an essential role.
Cells can move as a collective, or independently. Movement of an individual cell requires a series of carefully controlled steps. Among them, a cell must break contacts with its neighbor cells and change its connections to the proteins and fibers around it. In addition, it must sense and follow a chemical path through the tissue it lies in. To do this, a cell changes shape, molding its membrane into flaps or feet called protrusions reaching in the direction it is traveling. Actin, among a variety of other molecules, is involved in all of these steps, but especially the shape change, when it gathers inside the cell membrane to help form the protrusions. Continue reading “Actin’s Many Roles”