An adult female Hawaiian bobtail squid, Euprymna scolopes, with its mantle cavity exposed from the underside. Some internal organs are visible, including the two lobes of the light organ that contains bioluminescent bacteria, Vibrio fischeri. The light organ includes accessory tissues like an ink sac (black) that serves as a shutter, and a silvery reflector that directs the light out of the underside of the animal.

This image shows a computer-generated, three-dimensional map of the rotavirus structure. This virus infects humans and other animals and causes severe diarrhea in infants and young children. By the age of five, almost every child in the world has been infected with this virus at least once. Scientists have found a vaccine against rotavirus, so in the United States there are very few fatalities, but in developing countries and in places where the vaccine is unavailable, this virus is responsible for more than 200,000 deaths each year.

The rotavirus comprises three layers: the outer, middle and inner layers. On infection, the outer layer is removed, leaving behind a "double-layered particle." Researchers have studied the structure of this double-layered particle with a transmission electron microscope. Many images of the virus at a magnification of ~50,000x were acquired, and computational analysis was used to combine the individual particle images into a three-dimensional reconstruction.

The image was rendered by Melody Campbell (PhD student at TSRI). Work that led to the 3D map was published in Campbell et al. Movies of ice-embedded particles enhance resolution in electron cryo-microscopy. Structure. 2012;20(11):1823-8. PMCID: PMC3510009.

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

Cells keep time to know when to retire.

This video shows the structure of the pore-forming protein VDAC-1 from humans. This molecule mediates the flow of products needed for metabolism--in particular the export of ATP--across the outer membrane of mitochondria, the power plants for eukaryotic cells. VDAC-1 is involved in metabolism and the self-destruction of cells--two biological processes central to health.

Related to videos 2570 and 2571.

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).

This is a tomographic reconstruction of a mitochondrion from an insect flight muscle. Mitochondria are cellular compartments that are best known as the powerhouses that convert energy from the food into energy that runs a range of biological processes. Nearly all our cells have mitochondria.

Myotonic dystrophy is thought to be caused by the binding of a protein called Mbnl1 to abnormal RNA repeats. In these two images of the same muscle precursor cell, the top image shows the location of the Mbnl1 splicing factor (green) and the bottom image shows the location of RNA repeats (red) inside the cell nucleus (blue). The white arrows point to two large foci in the cell nucleus where Mbnl1 is sequestered with RNA.

Researchers have learned much of what they know about membranes by constructing artificial membranes in the laboratory. In artificial membranes, different lipids separate from each other based on their physical properties, forming small islands called lipid rafts.

Protein kinases—enzymes that add phosphate groups to molecules—are cancer chemotherapy targets because they play significant roles in almost all aspects of cell function, are tightly regulated, and contribute to the development of cancer and other diseases if any alterations to their regulation occur. Genetic abnormalities affecting the c-Abl tyrosine kinase are linked to chronic myelogenous leukemia, a cancer of immature cells in the bone marrow. In the noncancerous form of the protein, binding of a myristoyl group to the kinase domain inhibits the activity of the protein until it is needed (top left shows the inactive form, top right shows the open and active form). The cancerous variant of the protein, called Bcr-Abl, lacks this autoinhibitory myristoyl group and is continually active (bottom). ATP is shown in green bound in the active site of the kinase.

Find these in the RCSB Protein Data Bank: c-Abl tyrosine kinase and regulatory domains (PDB entry 1OPL) and F-actin binding domain (PDB entry 1ZZP).

Undifferentiated embryonic stem cells cease to exist a few days after conception. In this image, ES cells are shown to differentiate into sperm, muscle fiber, hair cells, nerve cells, and cone cells.

A color-coded, 3D model of a rat pancreatic β cell. This type of cell produces insulin, a hormone that helps regulate blood sugar. Visible are mitochondria (pink), insulin vesicles (yellow), the nucleus (dark blue), and the plasma membrane (teal). This model was created based on soft X-ray tomography (SXT) images.

A fruit fly ovary, shown here, contains as many as 20 eggs. Fruit flies are not merely tiny insects that buzz around overripe fruit—they are a venerable scientific tool. Research on the flies has shed light on many aspects of human biology, including biological rhythms, learning, memory, and neurodegenerative diseases. Another reason fruit flies are so useful in a lab (and so successful in fruit bowls) is that they reproduce rapidly. About three generations can be studied in a single month.

Related to image 3656. This image was part of the Life: Magnified exhibit that ran from June 3, 2014, to January 21, 2015, at Dulles International Airport.

Fruit flies are a common model organism for basic medical research.

An atomic force microscopy image shows DNA folded into an intricate, computer-designed structure. Image is featured on Biomedical Beat blog post Cool Image: DNA Origami. See also related image 3689 .

Time-lapse video of yeast cells undergoing cell division. Nuclear envelopes are shown in green, and spindle pole bodies, which help pull apart copied genetic information, are shown in magenta. This video was captured using wide-field microscopy with deconvolution.

Related to images 6791, 6792, 6793, 6794, 6797, 6798, and video 6796.

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.

RNA incorporated into the CRISPR surveillance complex is positioned to scan across foreign DNA. Cryo-EM density from a 3Å reconstruction is shown as a yellow mesh.

A computer-generated sketch of a DNA origami folded into a flower-and-bird structure. See also related image 3690.

Blood vessels at the back of the eye (retina) are used to diagnose glaucoma and diabetic eye disease. They also display characteristic changes in people with high blood pressure. In the image, the vessels appear green. It's not actually the vessels that are stained green, but rather filaments of a protein called actin that wraps around the vessels. Most of the red blood cells were replaced by fluid as the tissue was prepared for the microscope. The tiny red dots are red blood cells that remain in the vessels. The image was captured using confocal and 2-photon excitation microscopy for a project related to neurofibromatosis.

Automated crystal screening systems such as the one shown here are becoming a common feature at synchrotron and other facilities where high-throughput crystal structure determination is being carried out. These systems rapidly screen samples to identify the best candidates for further study.

As this cell was undergoing cell division, it was imaged with two microscopy techniques: differential interference contrast (DIC) and confocal. The DIC view appears in blue and shows the entire cell. The confocal view appears in pink and shows the chromosomes.

This video shows an instance of abnormal mitosis where chromosomes are late to align. The video demonstrates the spindle checkpoint in action: just one unaligned chromosome can delay anaphase and the completion of mitosis. The cells shown are S3 tissue cultured cells from Xenopus laevis, African clawed frog.

The cone cell of the eye allows you to see in color. Appears in the NIGMS booklet Inside the Cell.

For thousands of years, Chinese herbalists have treated malaria using Chang Shan, a root extract from a type of hydrangea that grows in Tibet and Nepal. Recent studies have suggested Chang Shan can also reduce scar formation, treat multiple sclerosis and even slow cancer progression.

Ribonucleic acid (RNA) has a sugar-phosphate backbone and the bases adenine (A), cytosine (C), guanine (G), and uracil (U). Featured in The New Genetics.

See image 2554 for an unlabeled version of this illustration.

The worm Caenorhabditis elegans is a popular laboratory animal because its small size and fairly simple body make it easy to study. Scientists use this small worm to answer many research questions in developmental biology, neurobiology, and genetics. This image, which was taken with transmission electron microscopy (TEM), shows a cross-section through C. elegans, revealing various internal structures labeled in the image. You can find a high-resolution image without the annotations at image 5759.

The image is from a figure in an article published in the journal eLife.

Actin (purple), microtubules (yellow), and nuclei (green) are labeled in these cells by immunofluorescence. This image won first place in the Nikon 2003 Small World photo competition.

2.5Å resolution reconstruction of rabbit muscle aldolase collected on a FEI/Thermo Fisher Titan Krios with energy filter and image corrector.

Like a pulsing blue shower, E. coli cells flash in synchrony. Genes inserted into each cell turn a fluorescent protein on and off at regular intervals. When enough cells grow in the colony, a phenomenon called quorum sensing allows them to switch from blinking independently to blinking in unison. Researchers can watch waves of light propagate across the colony. Adjusting the temperature, chemical composition or other conditions can change the frequency and amplitude of the waves. Because the blinks react to subtle changes in the environment, synchronized oscillators like this one could one day allow biologists to build cellular sensors that detect pollutants or help deliver drugs.

The enzyme Dicer generates microRNAs by chopping larger RNA molecules into tiny Velcro^®-like pieces. MicroRNAs stick to mRNA molecules and prevent the mRNAs from being made into proteins. See image 2556 for an unlabeled version of this illustration. Featured in The New Genetics.

Nucleotides in DNA are copied into RNA, where they are read three at a time to encode the amino acids in a protein. Many parts of a protein fold as the amino acids are strung together.

See image 2510 for a labeled version of this illustration.

Featured in The Structures of Life.

A number of environmental factors cause DNA mutations that can lead to cancer: toxins in cigarette smoke, sunlight and other radiation, and some viruses.

Lysosomes have powerful enzymes and acids to digest and recycle cell materials.

Ecteinascidin 743 (ET-743, brand name Yondelis), was discovered and isolated from a sea squirt, Ecteinascidia turbinata, by NIGMS grantee Kenneth Rinehart at the University of Illinois. It was synthesized by NIGMS grantees E.J. Corey and later by Samuel Danishefsky. Multiple versions of this structure are available as entries 2790-2797.

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.

In the worm C. elegans, double-stranded RNA made in neurons can silence matching genes in a variety of cell types through the transport of RNA between cells. The head region of three worms that were genetically modified to express a fluorescent protein were imaged and the images were color-coded based on depth. The worm on the left lacks neuronal double-stranded RNA and thus every cell is fluorescent. In the middle worm, the expression of the fluorescent protein is silenced by neuronal double-stranded RNA and thus most cells are not fluorescent. The worm on the right lacks an enzyme that amplifies RNA for silencing. Surprisingly, the identities of the cells that depend on this enzyme for gene silencing are unpredictable. As a result, worms of identical genotype are nevertheless random mosaics for how the function of gene silencing is carried out. For more, see journal article and press release. Related to image 6534.

This ribbon drawing of a protein hand drawn and colored by researcher Jane Richardson in 1981 helped originate the ribbon representation of proteins that is now ubiquitous in molecular graphics. The drawing shows the 3-dimensional structure of the protein triose phosphate isomerase. The green arrows represent the barrel of eight beta strands in this structure and the brown spirals show the protein's eight alpha helices. A black and white version of this drawing originally illustrated a review article in Advances in Protein Chemistry, volume 34, titled "Anatomy and Taxonomy of Protein Structures." The illustration was selected as Picture of The Day on the English Wikipedia for November 19, 2009. Other important and beautiful images of protein structures by Jane Richardson are available in her Wikimedia gallery.

Actin is an essential protein in a cell's skeleton (cytoskeleton). It forms a dense network of thin filaments in the cell. Here, researchers have used a technique called stochastic optical reconstruction microscopy (STORM) to visualize the actin network in a cell in three dimensions. The actin strands were labeled with a dye called Alexa Fluor 647-phalloidin.  This image appears in a study published by Nature Methods, which reports how researchers use STORM to visualize the cytoskeleton.

A large number of proteins interact with the hormone insulin as it is produced in and secreted from the beta cells of the pancreas. In this image, the interactions of TMEM24 protein (green) and insulin (red) in pancreatic beta cells are shown in yellow. More information about the research behind this image can be found in a Biomedical Beat Blog posting from November 2013.

Spinal nerves are part of the peripheral nervous system. They run within the spinal column to carry nerve signals to and from all parts of the body. The spinal nerves enable all the movements we do, from turning our heads to wiggling our toes, control the movements of our internal organs, such as the colon and the bladder, as well as allow us to feel touch and the location of our limbs.

NIGMS staff are located in the Natcher Building on the NIH campus.

These images show frog cells in interphase. The cells are Xenopus XL177 cells, which are derived from tadpole epithelial cells. The microtubules are green and the chromosomes are blue. Related to 3442.

Ribonucleic acid (RNA) has a sugar-phosphate backbone and the bases adenine (A), cytosine (C), guanine (G), and uracil (U). See image 2555 for a labeled version of this illustration. Featured in The New Genetics.

Los ritmos circadianos son cambios físicos, mentales y de comportamiento que siguen un ciclo de 24 horas. Los ritmos circadianos se ven influenciados por la luz y están regulados por el núcleo supraquiasmático del cerebro, a veces denominado el reloj principal.

Vea 6613 para la versión en inglés de esta infografía.

This fingertip-shaped group of lights is a microscopic crystal called a quantum dot. About 10,000 times thinner than a sheet of paper, the dot radiates brilliant colors under ultraviolet light. Dots such as this one allow researchers to label and track individual molecules in living cells and may be used for speedy disease diagnosis, DNA testing, and screening for illegal drugs.

This image shows the uncontrolled growth of cells in squamous cell carcinoma, the second most common form of skin cancer. If caught early, squamous cell carcinoma is usually not life-threatening.

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

The three neurons (red) visible in this image were derived from human embryonic stem cells. Undifferentiated stem cells are green here. Image and caption information courtesy of the California Institute for Regenerative Medicine.

Scientists from Argonne National Laboratory's Advanced Photon Source (APS) display the first X-ray diffraction pattern obtained from a protein crystal using a split X-ray beam, the first of its kind at APS. The scientists shown are (from left to right): Oleg Makarov, Ruslan Sanishvili, Robert Fischetti (project manager), Sergey Stepanov, and Ward Smith.

The white circle in this image is a Petri dish, named for its inventor, Julius Richard Petri. These dishes are one of the most common pieces of equipment in biology labs, where researchers use them to grow cells.

X-ray co-crystal structure of Src kinase bound to a DNA-templated macrocycle inhibitor. Related to 3414, 3415, 3416, 3417, 3418, and 3419.