A peripheral nerve cell made from human embryonic stem cell-derived neural crest stem cells. The nucleus is shown in blue, and nerve cell proteins peripherin and beta-tubulin (Tuj1) are shown in green and red, respectively. Related to image 3263.

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.

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.

Image showing rhabdomeres (red), the light-sensitive structures in the fruit fly retina, and rhodopsin-4 (blue), a light-sensing molecule.

A crystal of hen egg lysozyme protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

T cells are white blood cells that are important in defending the body against bacteria, viruses and other pathogens. Each T cell carries proteins, called T-cell receptors, on its surface that are activated when they come in contact with an invader. This activation sets in motion a cascade of biochemical changes inside the T cell to mount a defense against the invasion. Scientists have been interested for some time what happens after a T-cell receptor is activated. One obstacle has been to study how this signaling cascade, or pathway, proceeds inside T cells.

In this image, researchers have created a T-cell receptor pathway consisting of 12 proteins outside the cell on an artificial membrane. The image shows two key steps during the signaling process: clustering of a protein called linker for activation of T cells (LAT) (blue) and polymerization of the cytoskeleton protein actin (red). The findings show that the T-cell receptor signaling proteins self-organize into separate physical and biochemical compartments. This new system of studying molecular pathways outside the cells will enable scientists to better understand how the immune system combats microbes or other agents that cause infection.

To learn more how researchers assembled this T-cell receptor pathway, see this press release from HHMI's Marine Biological Laboratory Whitman Center. Related to video 3786.

A humorous treatment of the concept of a cycling cell.

You are face to face with a 6-day-old zebrafish larva. What look like eyes will become nostrils, and the bulges on either side will become eyes. Scientists use fast-growing, transparent zebrafish to see body shapes form and organs develop over the course of just a few days. Images like this one help researchers understand how gene mutations can lead to facial abnormalities such as cleft lip and palate in people.

This image won a 2016 FASEB BioArt award. In addition, NIH Director Francis Collins featured this on his blog on January 26, 2017.

Hippocampal cells in culture with a neuron in green, showing hundreds of the small protrusions known as dendritic spines. The dendrites of other neurons are labeled in blue, and adjacent glial cells are shown in red.

Arranging exons in different patterns, called alternative splicing, enables cells to make different proteins from a single gene. See image 2553 for a labeled version of this illustration. Featured in The New Genetics.

A colony of human embryonic stem cells (light blue) grows on fibroblasts (dark blue).

Like tractor-trailers on a highway, small sacs called vesicles transport substances within cells. This image tracks the motion of vesicles in a living cell. The short red and yellow marks offer information on vesicle movement. The lines spanning the image show overall traffic trends. Typically, the sacs flow from the lower right (blue) to the upper left (red) corner of the picture. Such maps help researchers follow different kinds of cellular processes as they unfold.

A computer model shows how the endoplasmic reticulum is close to and almost wraps around mitochondria in the cell. The endoplasmic reticulum is lime green and the mitochondria are yellow. This image relates to a July 27, 2009 article in Computing Life.

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.

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.

X-ray co-crystal structure of Src kinase bound to a DNA-templated macrocycle inhibitor. Related to 3413, 3414, 3415, 3417, 3418, and 3419.

Three views of the entire nuclear lamina of a HeLa cell produced by tilted light sheet 3D single-molecule super-resolution imaging using a platform termed TILT3D.
See 6572 for a 3D view of this structure.

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.

Cross section of human skeletal muscle. Image taken with a confocal fluorescent light microscope.

The receptor is shown bound to an inverse agonist, ZM241385.

The green spots in this mouse brain are cells labeled with Calling Cards, a technology that records molecular events in brain cells as they mature. Understanding these processes during healthy development can guide further research into what goes wrong in cases of neuropsychiatric disorders. Also fluorescently labeled in this video are neurons (red) and nuclei (blue). Calling Cards and its application are described in the Cell paper “Self-Reporting Transposons Enable Simultaneous Readout of Gene Expression and Transcription Factor Binding in Single Cells” by Moudgil et al.; and the Proceedings of the National Academy of Sciences paper “A viral toolkit for recording transcription factor–DNA interactions in live mouse tissues” by Cammack et al. This video was created for the NIH Director’s Blog post The Amazing Brain: Tracking Molecular Events with Calling Cards.

Related to image 6780.

Using an electrode, researchers apply an electrical pulse onto a piece of muscle tissue affected by Huntington's disease.

A computer model of the cell membrane, where the plasma membrane is red, endoplasmic reticulum is yellow, and mitochondria are blue. This image relates to a July 27, 2009 article in Computing Life.

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.

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 1047, image 1048, image 1049,  image 1051 and image 1052.

The green in this image highlights a protein called TonB, which is produced by many gram-negative bacteria, including those that cause typhoid fever, meningitis and dysentery. TonB lets bacteria take up iron from the host's body, which they need to survive. More information about the research behind this image can be found in a Biomedical Beat Blog posting from August 2013.

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.

The lubber grasshopper, found throughout the southern United States, is frequently used in biology classes to teach students about the respiratory system of insects. Unlike mammals, which have red blood cells that carry oxygen throughout the body, insects have breathing tubes that carry air through their exoskeleton directly to where it's needed. This image shows the breathing tubes embedded in the weblike sheath cells that cover developing egg chambers.

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

Acetylsalicylate (bottom) is the aspirin of today. Adding a chemical tag called an acetyl group (shaded box, bottom) to a molecule derived from willow bark (salicylate, top) makes the molecule less acidic (and easier on the lining of the digestive tract), but still effective at relieving pain. See image 2530 for a labeled version of this illustration. Featured in Medicines By Design.

Luciferase-based imaging enables visualization and quantification of internal organs and transplanted cells in live adult zebrafish. In this image, a cardiac muscle-restricted promoter drives firefly luciferase expression.
For imagery of both the lateral and overhead view go to 3556.
For imagery of the lateral view go to 3558.
For more information about the illumated area go to 3559.

To splice a human gene (in this case, the one for insulin) into a plasmid, scientists take the plasmid out of an E. coli bacterium, cut the plasmid with a restriction enzyme, and splice in insulin-making human DNA. The resulting hybrid plasmid can be inserted into another E. coli bacterium, where it multiplies along with the bacterium. There, it can produce large quantities of insulin. See image 2564 for an unlabeled version of this illustration. Featured in The New Genetics.

The activator cancer cell culture, right, contains a chemical that causes the cells to emit light when in the presence of immune cells.

In this video, Rice University scientists used molecular modeling with a mathematical algorithm called AWSEM (for associative memory, water-mediated, structure and energy model) and structural data to analyze how a transcription factor called nuclear factor kappa B (NFkB) is removed from DNA to stop gene activation. AWSEM uses the interacting energies of their components to predict how proteins fold. At the start, the NFkB dimer (green and yellow, in the center) grips DNA (red, to the left), which activates the transcription of genes. IkB (blue, to the right), an inhibitor protein, stops transcription when it binds to NFkB and forces the dimer to twist and release its hold on DNA. The yellow domain at the bottom of IkB is the PEST domain, which binds first to NFkB. For more details about this mechanism called molecular stripping, see here.

This image shows neonatal mouse heart cells. These cells were grown in the lab on a chip that aligns the cells in a way that mimics what is normally seen in the body. Green shows the muscle protein toponin I. Red indicates the muscle protein actin, and blue indicates the cell nuclei. The work shown here was part of a study attempting to grow heart tissue in the lab to repair damage after a heart attack. Image and caption information courtesy of the California Institute for Regenerative Medicine. Related to images 3281 and 3282.

Ribosomes are complex machines made up of more than 50 proteins and three or four strands of genetic material called ribosomal RNA (rRNA). The busy cellular machines make proteins, which are critical to almost every structure and function in the cell. To do so, they read protein-building instructions, which come as strands of messenger RNA. Ribosomes are found in all forms of cellular life—people, plants, animals, even bacteria. This illustration of a bacterial ribosome was produced using detailed information about the position of every atom in the complex. Several antibiotic medicines work by disrupting bacterial ribosomes but leaving human ribosomes alone. Scientists are carefully comparing human and bacterial ribosomes to spot differences between the two. Structures that are present only in the bacterial version could serve as targets for new antibiotic medications.

A growing Vibrio cholerae (cholera) biofilm. Cholera bacteria form colonies called biofilms that enable them to resist antibiotic therapy within the body and other challenges to their growth.

Each slightly curved comma shape represents an individual bacterium from assembled confocal microscopy images. Different colors show each bacterium’s position in the biofilm in relation to the surface on which the film is growing.

The "epigenetic code" controls gene activity with chemical tags that mark DNA (purple diamonds) and the "tails" of histone proteins (purple triangles). These markings help determine whether genes will be transcribed by RNA polymerase. Genes hidden from access to RNA polymerase are not expressed. See image 2562 for an unlabeled version of this illustration. Featured in The New Genetics.

Proteins are long chains of amino acids. Each protein has a unique amino acid sequence. It is still a mystery how a protein folds into the proper shape based on its sequence. Scientists hope that one day they can "watch" this folding process for any given protein. The dream has been realized, at least partially, through the use of computer simulation.

This image shows the long, branched structures (axons) of nerve cells. Running horizontally across the middle of the photo is an axon wrapped in rings made of actin protein (green), which plays important roles in nerve cells. The image was captured with a powerful microscopy technique that allows scientists to see single molecules in living cells in real time. The technique is called stochastic optical reconstruction microscopy (STORM). It is based on technology so revolutionary that its developers earned the 2014 Nobel Prize in Chemistry. More information about this image can be found in: K. Xu, G. Zhong, X. Zhuang. Actin, spectrin and associated proteins form a periodic cytoskeleton structure in axons. Science 339, 452-456 (2013).

The body uses a variety of ion channels to transport small molecules across cell membranes.

A special "messy" region of a potassium ion channel is important in its function.

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.

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

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 goal of the Protein Structure Initiative (PSI) is to determine the three-dimensional shapes of a wide range of proteins by solving the structures of representative members of each protein family found in nature. The collection of structures should serve as a valuable resource for biomedical research scientists.

To splice a human gene into a plasmid, scientists take the plasmid out of an E. coli bacterium, cut the plasmid with a restriction enzyme, and splice in human DNA. The resulting hybrid plasmid can be inserted into another E. coli bacterium, where it multiplies along with the bacterium. There, it can produce large quantities of human protein. See image 2565 for a labeled version of this illustration. Featured in The New Genetics.

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.

The 3D single-molecule super-resolution reconstruction of the entire nuclear lamina in a HeLa cell was acquired using the TILT3D platform. TILT3D combines a tilted light sheet with point-spread function (PSF) engineering to provide a flexible imaging platform for 3D single-molecule super-resolution imaging in mammalian cells.
See 6573 for 3 seperate views of this structure.

Three-dimensional reconstruction of a tubular matrix in a thin section of the peripheral endoplasmic reticulum between the plasma membranes of the cell.
The endoplasmic reticulum (ER) is a continuous membrane that extends like a net from the envelope of the nucleus outward to the cell membrane. The ER plays several roles within the cell, such as in protein and lipid synthesis and transport of materials between organelles.
Shown here are super-resolution microscopic images of the peripheral ER showing the structure of an ER tubular matrix between the plasma membranes of the cell. See image 5857 for a more detailed view of the area outlined in white in this image. For another view of the ER tubular matrix see image 5855

Sulfite oxidase is an enzyme that is essential for normal neurological development in children. This video shows the active site of the enzyme and its molybdenum cofactor visible as a faint ball-and-stick representation buried within the protein. The positively charged channel (blue) at the active site contains a chloride ion (green) and three water molecules (red). As the protein oscillates, one can see directly down the positively charged channel. At the bottom is the molybdenum atom of the active site (light blue) and its oxo group (red) that is transferred to sulfite to form sulfate in the catalytic reaction.