A Janus particle being used to activate a T cell, a type of immune cell. A Janus particle is a specialized microparticle with different physical properties on its surface, and this one is coated with nickel on one hemisphere and anti-CD3 antibodies (light blue) on the other. The nickel enables the Janus particle to be moved using a magnet, and the antibodies bind to the T cell and activate it. The T cell in this video was loaded with calcium-sensitive dye to visualize calcium influx, which indicates activation. The intensity of calcium influx was color coded so that warmer color indicates higher intensity. Being able to control Janus particles with simple magnets is a step toward controlling individual cells’ activities without complex magnetic devices.

More details can be found in the Angewandte Chemie paper “Remote control of T cell activation using magnetic Janus particles” by Lee et al. This video was captured using epi-fluorescence microscopy.

Related to video 6801.

This tropical scene, reminiscent of a postcard from Key West, is actually a petri dish containing an artistic arrangement of genetically engineered bacteria. The image showcases eight of the fluorescent proteins created in the laboratory of the late Roger Y. Tsien, a cell biologist at the University of California, San Diego. Tsien, along with Osamu Shimomura of the Marine Biology Laboratory and Martin Chalfie of Columbia University, share the 2008 Nobel Prize in chemistry for their work on green fluorescent protein-a naturally glowing molecule from jellyfish that has become a powerful tool for studying molecules inside living cells.

Trajectories of single molecule labeled cell surface receptors. This is an example of NIH-supported research on single-cell analysis. Related to 2798 , 2799, 2800, 2802 and 2803.

Macrophages (green) are the professional eaters of our immune system. They are constantly surveilling our tissues for targets—such as bacteria, dead cells, or even cancer—and clearing them before they can cause harm. In this image, researchers were testing how macrophages responded to different molecules that were attached to silica beads (magenta) coated with a lipid bilayer to mimic a cell membrane.

Find more information on this image in the NIH Director’s Blog post "How to Feed a Macrophage."

This image shows a normal fibroblast, a type of cell that is common in connective tissue and frequently studied in research labs. This cell has a healthy skeleton composed of actin (red) and microtubles (green). Actin fibers act like muscles to create tension and microtubules act like bones to withstand compression.

This image was part of the Life: Magnified exhibit that ran from June 3, 2014, to January 21, 2015, at Dulles International Airport.

As an egg cell develops, a process called polarization controls what parts ultimately become the embryo's head and tail. This picture shows an egg of the fruit fly Drosophila. Red and green mark two types of signaling proteins involved in polarization. Disrupting these signals can scramble the body plan of the embryo, leading to severe developmental disorders.

The photo shows a confocal microscopy image of perineuronal nets (PNNs), which are specialized extracellular matrix (ECM) structures in the brain. The PNN surrounds some nerve cells in brain regions including the cortex, hippocampus and thalamus. Researchers study the PNN to investigate their involvement stabilizing the extracellular environment and forming nets around nerve cells and synapses in the brain. Abnormalities in the PNNs have been linked to a variety of disorders, including epilepsy and schizophrenia, and they limit a process called neural plasticity in which new nerve connections are formed. To visualize the PNNs, researchers labeled them with Wisteria floribunda agglutinin (WFA)-fluorescein. Related to image 3741.

A light microscope image of a cell from the endosperm of an African globe lily (Scadoxus katherinae). This is one frame of a time-lapse sequence that shows cell division in action. The lily is considered a good organism for studying cell division because its chromosomes are much thicker and easier to see than human ones. Staining shows microtubules in red and chromosomes in blue. Here, condensed chromosomes are clearly visible and are starting to separate to form two new cells.

Confocal image showing high levels of the protein vimentin (white) at the edge zone of a quail embryo. Cell nuclei are labeled green. More specifically, this high-magnification (60X) image shows vimentin immunofluorescence in the edge zone (top of image) and inner zone (bottom of image) of a Stage 4 quail blastoderm. Vimentin expression (white) is shown merged with Sytox nuclear labeling (green) at the edge of the blastoderm. A thick vimentin filament runs circumferentially (parallel to the direction of the edge) that appears to delineate the transition between the edge zone and interior zone. Also shown are dense vimentin clusters or foci, which typically appear to be closely associated with edge cell nuclei. An NIGMS grant to Professor Garcia was used to purchase the confocal microscope that collected this image. Related to image 2808 and video 2809.

Learn about how bacteria and viruses differ, how they each can make you sick, and how they can or cannot be treated. Discover more resources from NIGMS’ Pathways collaboration with Scholastic. View the video on YouTube for closed captioning.

Embryonic stem cells store pre-activated Bax (red) in the Golgi, near the nucleus (blue). Featured in the June 21, 2012, issue of Biomedical Beat.

Hydra magnipapillata is an invertebrate animal used as a model organism to study developmental questions, for example the formation of the body axis.

Composite image of beta-galactosidase showing how cryo-EM’s resolution has improved dramatically in recent years. Older images to the left, more recent to the right. Related to image 5883. NIH Director Francis Collins featured this on his blog on January 14, 2016.

Amid a network of blood vessels and star-shaped support cells, neurons in the brain signal each other. The mists of color show the flow of important molecules like glucose and oxygen. This image is a snapshot from a 52-second simulation created by an animation artist. Such visualizations make biological processes more accessible and easier to understand.

It's probably most people's least favorite activity, but we still need to do it--take out our trash. Otherwise our homes will get cluttered and smelly, and eventually, we'll get sick. The same is true for our cells: garbage disposal is an ongoing and essential activity, and our cells have a dedicated waste-management system that helps keep them clean and neat. One major waste-removal agent in the cell is the lysosome. Lysosomes are small structures, called organelles, and help the body to dispose of proteins and other molecules that have become damaged or worn out.

This image shows a massive accumulation of lysosomes (visualized with LAMP1 immunofluorescence, in purple) within nerve cells that surround amyloid plaques (visualized with beta-amyloid immunofluorescence, in light blue) in a mouse model of Alzheimer's disease. Scientists have linked accumulation of lysosomes around amyloid plaques to impaired waste disposal in nerve cells, ultimately resulting in cell death.

Fruit fly sperm cells glow bright green when they express the gene for green fluorescent protein (GFP).

Living primary mouse embryonic fibroblasts. Mitochondria (green) stained with the mitochondrial membrane potential indicator, rhodamine 123. Nuclei (blue) are stained with DAPI. Caption from a November 26, 2012 news release from U Penn (Penn Medicine).

Cancer cells can change their migration phenotype, which includes their shape and the way that they move to invade different tissues. This movie shows breast cancer cells forming a tumor spheroid—a 3D ball of cancer cells—and invading the surrounding tissue. Images were taken using a laser scanning confocal microscope, and artificial intelligence (AI) models were used to segment and classify the images by migration phenotype. On the right side of the video, each phenotype is represented by a different color, as recognized by the AI program based on identifiable characteristics of those phenotypes. The movie demonstrates how cancer cells can use different migration modes during growth and metastasis—the spreading of cancer cells within the body.

This animation shows atoms of the HIV capsid, the shell that encloses the virus's genetic material. Scientists determined the exact structure of the capsid using a variety of imaging techniques and analyses. They then entered this data into a supercomputer to produce this image. Related to image 3477.

These smooth muscle cells were derived from human embryonic stem cells. The nuclei are stained blue, and the proteins of the cytoskeleton are stained green. Image and caption information courtesy of the California Institute for Regenerative Medicine.

The nucleolus is a small but very important protein complex located in the cell's nucleus. It forms on the chromosomes at the location where the genes for the RNAs are that make up the structure of the ribosome, the indispensable cellular machine that makes proteins from messenger RNAs.

However, how the nucleolus grows and maintains its structure has puzzled scientists for some time. It turns out that even though it looks like a simple liquid blob, it's rather well-organized, consisting of three distinct layers: the fibrillar center, where the RNA polymerase is active; the dense fibrillar component, which is enriched in the protein fibrillarin; and the granular component, which contains a protein called nucleophosmin. Researchers have now discovered that this multilayer structure of the nucleolus arises from difference in how the proteins in each compartment mix with water and with each other. These differences let them readily separate from each other into the three nucleolus compartments.

This video of nucleoli in the eggs of a commonly used lab animal, the frog Xenopus laevis, shows how each of the compartments (the granular component is shown in red, the fibrillarin in yellow-green, and the fibrillar center in blue) spontaneously fuse with each other on encounter without mixing with the other compartments. For more details on this research, see this press release from Princeton. Related to video 3791, image 3792 and image 3793.

Misfolded proteins (green) within mitochondria (red). Related to video 5877.

Network diagram showing a map of protein-protein interactions in a yeast (Saccharomyces cerevisiae) cell. This cluster includes 78 percent of the proteins in the yeast proteome. The color of a node represents the phenotypic effect of removing the corresponding protein (red, lethal; green, nonlethal; orange, slow growth; yellow, unknown).

Related to image 6355.

A light microscope image of cells from the endosperm of an African globe lily (Scadoxus katherinae). This is one frame of a time-lapse sequence that shows cell division in action. The lily is considered a good organism for studying cell division because its chromosomes are much thicker and easier to see than human ones. Staining shows microtubules in red and chromosomes in blue. Here, two cells have formed after a round of mitosis.

Related to images 1010, 1011, 1012, 1013, 1014, 1015, 1016, 1017, 1018, and 1021.

The nucleolinus is a cellular compartment that has been a lonely bystander in scientific endeavors. Although it's found in a range of species, its function has been mysterious—mainly because the structure is hard to visualize. An August 2010 study showed that the nucleolinus is crucial for cell division. When researchers zapped the structure with a laser, an egg cell didn't complete division. When the oocyte was fertilized after laser microsurgery (bottom right), the resulting zygote didn't form vital cell division structures (blue and yellow).

Fruit fly (Drosophila melanogaster) ovaries with DNA shown in magenta and actin filaments shown in light blue. This image was captured using a confocal laser scanning microscope.

Related to image 6806.

Cells progress through a cycle that consists of phases for growth (G1, S, and G2) and division (M). Cells become quiescent when they exit this cycle (G0). See image 2498 for an unlabeled version of this illustration.

Centrioles (green) anchor cilia (red), which project on the surface of pharynx cells of the freshwater planarian Schmidtea mediterranea. Centrioles require cellular structures called centrosomes for assembly in other animal species, but this flatworm known for its regenerative ability was unexpectedly found to lack centrosomes. From a Stowers University news release.

Cell mopping up.

Researchers used fluorescence in situ hybridization (FISH) to confirm the presence of long range DNA-DNA interactions in mouse embryonic stem cells. Here, two loci labeled in green (Oct4) and red that are 13 Mb apart on linear DNA are frequently found to be in close proximity. DNA-DNA colocalizations like this are thought to both reflect and contribute to cell type specific gene expression programs.

This graphic that resembles a firework was created from a picture of a fruit fly spermatid. This fruit fly spermatid recycles various molecules, including malformed or damaged proteins. Actin filaments (red) in the cell draw unwanted proteins toward a barrel-shaped structure called the proteasome (green clusters), which degrades the molecules into their basic parts for re-use.

Skins cells were reprogrammed into heart muscle cells. The cells highlighted in green are remaining skin cells. Red indicates a protein that is unique to heart muscle. The technique used to reprogram the skin cells into heart cells could one day be used to mend heart muscle damaged by disease or heart attack. Image and caption information courtesy of the California Institute for Regenerative Medicine.

Borrelia burgdorferi is a spirochete, a class of long, slender bacteria that typically take on a coiled shape. Infection with this bacterium causes Lyme disease.

Salk researchers captured the structure of a protein complex called an intasome (center) that lets viruses similar to HIV establish permanent infection in their hosts. The intasome hijacks host genomic material, DNA (white) and histones (beige), and irreversibly inserts viral DNA (blue). The image was created by Jamie Simon and Dmitry Lyumkis. Work that led to the 3D map was published in: Ballandras-Colas A, Brown M, Cook NJ, Dewdney TG, Demeler B, Cherepanov P, Lyumkis D, & Engelman AN. (2016). Cryo-EM reveals a novel octameric integrase structure for ?-retroviral intasome function. Nature, 530(7590), 358—361

It has been said that gastrulation is the most important event in a person's life. This part of early embryonic development transforms a simple ball of cells and begins to define cell fate and the body axis. In a study published in Science magazine, NIGMS grantee Bob Goldstein and his research group studied how contractions of actomyosin filaments in C. elegans and Drosophila embryos lead to dramatic rearrangements of cell and embryonic structure. In these images, myosin (green) and plasma membrane (red) are highlighted at four timepoints in gastrulation in the roundworm C. elegans. The blue highlights in the top three frames show how cells are internalized, and the site of closure around the involuting cells is marked with an arrow in the last frame. See related image 3297.

This montage of tiny, transparent C. elegans--or roundworms--may offer insight into understanding human infertility. Researchers used fluorescent dyes to label the worm cells and watch the process of sex cell division, called meiosis, unfold as nuclei (blue) move through the tube-like gonads. Such visualization helps the scientists identify mechanisms that enable these roundworms to reproduce successfully. Because meiosis is similar in all sexually reproducing organisms, what the scientists learn could apply to humans.

These yeast cells were exposed to a glucose (sugar) shortage. This caused the cells to compartmentalize HMGCR (green)—an enzyme involved in making cholesterol—to a patch on the nuclear envelope next to the vacuole/lysosome (purple). This process enhanced HMGCR activity and helped the yeast adapt to the glucose shortage. Researchers hope that understanding how yeast regulate cholesterol could ultimately lead to new ways to treat high cholesterol in people. This image was captured using a fluorescence microscope.

Image of Streptococcus, a type (genus) of spherical bacteria that can colonize the throat and back of the mouth. Stroptococci often occur in pairs or in chains, as shown here.

The feeding tube, or pharynx, of a planarian worm with cilia shown in red and muscle fibers shown in green

Cell-like compartments that spontaneously emerged from scrambled frog eggs, with nuclei (blue) from frog sperm. Endoplasmic reticulum (red) and microtubules (green) are also visible. Video created using confocal microscopy.

For more photos of cell-like compartments from frog eggs view: 6584, 6585, 6586, 6591, 6592, and 6593.

For videos of cell-like compartments from frog eggs view: 6587, 6588, 6589.

Lysosomes (yellow) and detyrosinated microtubules (light blue). Lysosomes are bubblelike organelles that take in molecules and use enzymes to break them down. Microtubules are strong, hollow fibers that provide structural support to cells. The researchers who took this image found that in epithelial cells, detyrosinated microtubules are a small subset of fibers, and they concentrate lysosomes around themselves. This image was captured using Stochastic Optical Reconstruction Microscopy (STORM).

Related to images 6890, 6891, and 6892.

During embryonic development, transcription factors (proteins that regulate gene expression) govern the differentiation of cells into separate tissues and organs. Researchers at Cincinnati Children's Hospital Medical Center used mice to study the development of certain internal organs, including the liver, pancreas, duodenum (beginning part of the small intestine), gall bladder and bile ducts. They discovered that transcription factor Sox17 guides some cells to develop into liver cells and others to become part of the pancreas or biliary system (gall bladder, bile ducts and associated structures). The separation of these two distinct cell types (liver versus pancreas/biliary system) is complete by embryonic day 8.5 in mice. The transcription factors PDX1 and Hes1 are also known to be involved in embryonic development of the pancreas and biliary system. This image shows mouse cells at embryonic day 10.5. The green areas show cells that will develop into the pancreas and/or duodenum(PDX1 is labeled green). The blue area near the bottom will become the gall bladder and the connecting tubes (common duct and cystic duct) that attach the gall bladder to the liver and pancreas (Sox17 is labeled blue). The transcription factor Hes1 is labeled red. The image was not published. A similar image (different plane of the section) was published in: Sox17 Regulates Organ Lineage Segregation of Ventral Foregut Progenitor Cells Jason R. Spence, Alex W. Lange, Suh-Chin J. Lin, Klaus H. Kaestner, Andrew M. Lowy, Injune Kim, Jeffrey A. Whitsett and James M. Wells, Developmental Cell, Volume 17, Issue 1, 62-74, 21 July 2009. doi:10.1016/j.devcel.2009.05.012

Multiphoton fluorescence image of cultured HeLa cells with a fluorescent protein targeted to the Golgi apparatus (orange), microtubules (green) and counterstained for DNA (cyan). Nikon RTS2000MP custom laser scanning microscope. See related images 3518, 3519, 3520, 3521.

This image shows collagen, a fibrous protein that's the main component of the extracellular matrix (ECM). Collagen is a strong, ropelike molecule that forms stretch-resistant fibers. The most abundant protein in our bodies, collagen accounts for about a quarter of our total protein mass. Among its many functions is giving strength to our tendons, ligaments and bones and providing scaffolding for skin wounds to heal. There are about 20 different types of collagen in our bodies, each adapted to the needs of specific tissues.

On the left, the boundary of a breast tumor (yellow) attaches to collagen fibers that are closest to it (green) using DDR2. On the right, a tumor without DDR2 remains disconnected from the collagen.

If a picture is worth a thousand words, what's a movie worth? For researchers studying cell migration, a "documentary" of fruit fly cells (bright green) traversing an egg chamber could answer longstanding questions about cell movement. See 2315 for video.

A fruit fly (Drosophila melanogaster) egg chamber with microtubules shown in green and actin filaments shown in red. Egg chambers are multicellular structures in fruit flies ovaries that each give rise to a single egg. Microtubules and actin filaments give the chambers structure and shape. This image was captured using a confocal microscope.

More information on the research that produced this image can be found in the Current Biology paper "Gatekeeper function for Short stop at the ring canals of the Drosophila ovary" by Lu et al.

An Arachnoidiscus diatom with a diameter of 190µm. Diatoms are microscopic algae that have cell walls made of silica, which is the strongest known biological material relative to its density. In Arachnoidiscus, the cell wall is a radially symmetric pillbox-like shell composed of overlapping halves that contain intricate and delicate patterns. Sometimes, Arachnoidiscus is called “a wheel of glass.”

This image was taken with the orientation-independent differential interference contrast microscope.

Learn how curiosity about the world and our cells is key to scientific discoveries. Discover more resources from NIGMS’ Pathways collaboration with Scholastic. View the video on YouTube for closed captioning.