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.

The G switch allows our bodies to respond rapidly to hormones. G proteins act like relay batons to pass messages from circulating hormones into cells. A hormone (red) encounters a receptor (blue) in the membrane of a cell. Next, a G protein (green) becomes activated and makes contact with the receptor to which the hormone is attached. Finally, the G protein passes the hormone's message to the cell by switching on a cell enzyme (purple) that triggers a response. See image 2536 and 2538 for other versions of this image. Featured in Medicines By Design.

Influenza A infects a host cell when hemagglutinin grips onto glycans on its surface. Neuraminidase, an enzyme that chews sugars, helps newly made virus particles detach so they can infect other cells. Related to 213.

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.

In many animals, the egg cell develops alongside sister cells. These sister cells are called nurse cells in the fruit fly (Drosophila melanogaster), and their job is to “nurse” an immature egg cell, or oocyte. Toward the end of oocyte development, the nurse cells transfer all their contents into the oocyte in a process called nurse cell dumping. This process involves significant shape changes on the part of the nurse cells (blue), which are powered by wavelike activity of the protein myosin (red). This image was captured using a confocal laser scanning microscope. Related to video 6754.

Stereo triplet of a sea urchin embryo stained to reveal actin filaments (orange) and microtubules (blue). This image is part of a series of images: image 1048, image 1049, image 1050, image 1051 and image 1052.

La sepsis o septicemia es la respuesta fulminante y extrema del cuerpo a una infección. En los Estados Unidos, más de 1.7 millones de personas contraen sepsis cada año. Sin un tratamiento rápido, la sepsis puede provocar daño de los tejidos, insuficiencia orgánica y muerte. El NIGMS apoya a muchos investigadores en su trabajo para mejorar el diagnóstico y el tratamiento de la sepsis.

Vea 6536 para la versión en inglés de esta infografía.

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.

A segment of siRNA, shown in red, guides a "slicer" protein called Argonaute (multi-colored twists and corkscrews) to the target RNA molecules.

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

This sculpture made of purple and clear glass beads depicts bacteriophage Phi174, a virus that infects bacteria. It rests on a surface that portrays an adaptive landscape, a conceptual visualization. The ridges represent the gene combinations associated with the greatest fitness levels of the virus, as measured by how quickly the virus can reproduce itself. Phi174 is an important model system for studies of viral evolution because its genome can readily be sequenced as it evolves under defined laboratory conditions.

Along with blood vessels (red) and nerve cells (green), this mouse brain shows abnormal protein clumps known as plaques (blue). These plaques multiply in the brains of people with Alzheimer's disease and are associated with the memory impairment characteristic of the disease. Because mice have genomes nearly identical to our own, they are used to study both the genetic and environmental factors that trigger Alzheimer's disease. Experimental treatments are also tested in mice to identify the best potential therapies for human patients.

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

A shell from the venomous cone snail Conus omaria, which lives in the Pacific and Indian oceans and eats other snails. University of Utah scientists discovered a new toxin in this snail species' venom, and say it will be a useful tool in designing new medicines for a variety of brain disorders, including Alzheimer's and Parkinson's diseases, depression, nicotine addiction and perhaps schizophrenia.

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.

Kupffer cells appear in the liver during the early stages of mammalian development and stay put throughout life to protect liver cells, clean up old red blood cells, and regulate iron levels. Source article Replenishing the Liver’s Immune Protections. Posted on December 12th, 2019 by Dr. Francis Collins.

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

Cells progress through a cycle that consists of phases for growth (blue, green, yellow) and division (red). Cells become quiescent when they exit this cycle (purple). See image 2499 for a labeled version of this illustration.

A typical animal cell, sliced open to reveal a cross-section of organelles.

This image shows an osteosarcoma cell with DNA in blue, energy factories (mitochondria) in yellow, and actin filaments—part of the cellular skeleton—in purple. One of the few cancers that originate in the bones, osteosarcoma is rare, with about a thousand new cases diagnosed each year in the United States.

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

Cells use bubble-like structures called vesicles (yellow) to import, transport, and export cargo and in cellular communication. A single cell may be filled with thousands of moving vesicles.

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

In 2006, scientists developed an optical microscopy technique enabling them to clearly see individual molecules within cells. In 2007, they took the technique, abbreviated STORM, a step further. They identified multicolored probes that let them peer into cells and clearly see multiple cellular components at the same time, such as these microtubules (green) and small hollows called clathrin-coated pits (red). Unlike conventional methods, the multicolor STORM technique produces a crisp and high resolution picture. A sharper view of how cellular components interact will likely help scientists answer some longstanding questions about cell biology.

The cytoskeleton (green) and DNA (purple) are highlighed in these cells by immunofluorescence.

In vivo vascular development in kdr:GFP frogs. Related to images 3403 and 3405.

A crystal of Bence Jones protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

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.

This image shows an abnormal, tetrapolar mitosis. Chromosomes are highlighted pink. The cells shown are S3 tissue cultured cells from Xenopus laevis, African clawed frog.

A 3-D model of the alkaloid serratezomine A shows the molecule's complex ring structure.

Planarians are freshwater flatworms that have powerful abilities to regenerate their bodies, which would seem to make them natural model organisms in which to study stem cells. But until recently, scientists had not been able to efficiently find the genes that regulate the planarian stem cell system. In this image, a single stem cell has given rise to a colony of stem cells in a planarian. Proliferating cells are red, and differentiating cells are blue. Quantitatively measuring the size and ratios of these two cell types provides a powerful framework for studying the roles of stem cell regulatory genes in planarians.

A team of chemists and physicists used nanotechnology and DNA's ability to self-assemble with matching RNA to create a new kind of chip for measuring gene activity. When RNA of a gene of interest binds to a DNA tile (gold squares), it creates a raised surface (white areas) that can be detected by a powerful microscope. This nanochip approach offers manufacturing and usage advantages over existing gene chips and is a key step toward detecting gene activity in a single cell. Featured in the February 20, 2008, issue of Biomedical Beat.

Inside the fertilized egg cell of a fruit fly, we see a type of myosin (related to the protein that helps muscles contract) made to glow by attaching a fluorescent protein. After fertilization, the myosin proteins are distributed relatively evenly near the surface of the embryo. The proteins temporarily vanish each time the cells' nuclei--initially buried deep in the cytoplasm--divide. When the multiplying nuclei move to the surface, they shift the myosin, producing darkened holes. The glowing myosin proteins then gather, contract, and start separating the nuclei into their own compartments.

Section of a fruit fly retina showing the light-sensing molecules rhodopsin-5 (blue) and rhodopsin-6 (red).

This image of a mammalian epithelial cell, captured in metaphase, was the winning image in the high- and super-resolution microscopy category of the 2012 GE Healthcare Life Sciences Cell Imaging Competition. The image shows microtubules (red), kinetochores (green) and DNA (blue). The DNA is fixed in the process of being moved along the microtubules that form the structure of the spindle.

The image was taken using the DeltaVision OMX imaging system, affectionately known as the "OMG" microscope, and was displayed on the NBC screen in New York's Times Square during the weekend of April 20-21, 2013. It was also part of the Life: Magnified exhibit that ran from June 3, 2014, to January 21, 2015, at Dulles International Airport.

The structure of the endothelium, the thin layer of cells that line our arteries and veins, is visible here. The endothelium is like a gatekeeper, controlling the movement of materials into and out of the bloodstream. Endothelial cells are held tightly together by specialized proteins that function like strong ropes (red) and others that act like cement (blue).

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

Sepsis is the body’s overactive and extreme response to an infection. More than 1.7 million people get sepsis each year in the United States. Without prompt treatment, sepsis can lead to tissue damage, organ failure, and death. Many NIGMS-supported researchers are working to improve sepsis diagnosis and treatment. Learn more with our sepsis featured topic page.

See 6551 for the Spanish version of this infographic.

Model of a protein, antigen 85B, that is the most abundant protein exported by Mycobacterium tuberculosis, which causes most cases of tuberculosis. Antigen 85B is involved in building the bacterial cell wall and is an attractive drug target. Based on its structure, scientists have suggested a new class of antituberculous drugs.

Real-time footage of Caenorhabditis elegans, a tiny roundworm, trapped by a carnivorous fungus, Arthrobotrys dactyloides. This fungus makes ring traps in response to the presence of C. elegans. When a worm enters a ring, the trap rapidly constricts so that the worm cannot move away, and the fungus then consumes the worm. The size of the imaged area is 0.7mm x 0.9mm.

This video was obtained with a polychromatic polarizing microscope (PPM) in white light that shows the polychromatic birefringent image with hue corresponding to the slow axis orientation. More information about PPM can be found in the Scientific Reports paper “Polychromatic Polarization Microscope: Bringing Colors to a Colorless World” by Shribak.

Gene transcription is a process by which the genetic information encoded in DNA is transcribed into RNA. It's essential for all life and requires the activity of proteins, called transcription factors, that detect where in a DNA strand transcription should start. In eukaryotes (i.e., those that have a nucleus and mitochondria), a protein complex comprising 14 different proteins is responsible for sniffing out transcription start sites and starting the process. This complex, called TFIID, represents the core machinery to which an enzyme, named RNA polymerase, can bind to and read the DNA and transcribe it to RNA. Scientists have used cryo-electron microscopy (cryo-EM) to visualize the TFIID-RNA polymerase-DNA complex in unprecedented detail. In this illustration, TFIID (blue) contacts the DNA and recruits the RNA polymerase (gray) for gene transcription. The start of the transcribed gene is shown with a flash of light. To learn more about the research that has shed new light on gene transcription, see this news release from Berkeley Lab. Related to video 5730.

A robot is transferring 96 purification columns to a vacuum manifold for subsequent purification procedures.

In the determination of protein structures by X-ray crystallography, this unique soft (l = 2.29Å) X-ray source is used to collect anomalous scattering data from protein crystals containing light atoms such as sulfur, calcium, zinc and phosphorous. These data can be used to image the protein.

Stained glomeruli in the kidney. The kidney is an essential organ responsible for disposing wastes from the body and for maintaining healthy ion levels in the blood. It works like a purifier by pulling break-down products of metabolism, such as urea and ammonium, from the bloodstream for excretion in urine. The glomerulus is a structure that helps filter the waste compounds from the blood. It consists of a network of capillaries enclosed within a Bowman's capsule of a nephron, which is the structure in which ions exit or re-enter the blood in the kidney.

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.

Pigment cells are cells that give skin its color. In fishes and amphibians, like frogs and salamanders, pigment cells are responsible for the characteristic skin patterns that help these organisms to blend into their surroundings or attract mates. The pigment cells are derived from neural crest cells, which are cells originating from the neural tube in the early embryo. This image shows pigment cells from pearl danio, a relative of the popular laboratory animal zebrafish. Investigating pigment cell formation and migration in animals helps answer important fundamental questions about the factors that control pigmentation in the skin of animals, including humans. Related to images 5754, 5755, 5757 and 5758.

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

Cilia (cilium in singular) are complex molecular machines found on many of our cells. One component of cilia is the doublet microtubule, a major part of cilia’s skeletons that give them support and shape. This animated video illustrates the structure of doublet microtubules, which contain 451 protein chains that were mapped using cryo-electron microscopy. Image can be found here 6548.

CellPack image of the H1N1 influenza virus, with hemagglutinin and neuraminidase glycoproteins in green and red, respectively, on the outer envelope (white); matrix protein in gray, and ribonucleoprotein particles inside the virus in red and green. Related to image 6356.

Automated methods using micromachined silicon are used at the Northeast Collaboratory for Structural Genomics to mount protein crystals for X-ray crystallography.

Recombinant proteins such as the prion protein shown here are often used to model how proteins misfold and sometimes polymerize in neurodegenerative disorders. This prion protein was expressed in E. coli, purified and fibrillized at pH 7. Image taken in 2004 for a research project by Roger Moore, Ph.D., at Rocky Mountain Laboratories that was published in 2007 in Biochemistry. This image was not used in the publication.

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.

X-ray co-crystal structure of Src kinase bound to a DNA-templated macrocycle inhibitor. Related to images 3413, 3414, 3415, 3416, 3417, and 3419.

Illustration of a sperm, the male reproductive cell.