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

Relapsing fever is caused by a bacterium and transmitted by certain soft-bodied ticks or body lice. The disease is seldom fatal in humans, but it can be very serious and prolonged. This scanning electron micrograph shows Borrelia hermsii (green), one of the bacterial species that causes the disease, interacting with red blood cells. Micrograph by Robert Fischer, NIAID.

For more information on this see, relapsing fever.

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

Colonies of bacteria growing despite high concentrations of antibiotics. These colonies are visible both by eye, as seen on the left, and by bioluminescence imaging, as seen on the right. The bioluminescent color indicates the metabolic activity of these bacteria, with their red centers indicating high metabolism.

More information about the research that produced this image can be found in the Antimicrobial Agents and Chemotherapy paper “Novel aminoglycoside-tolerant phoenix colony variants of Pseudomonas aeruginosa” by Sindeldecker et al.

Microfluidic chips have many uses in biology labs. The one shown here was used by bioengineers to study bacteria, allowing the researchers to synchronize their fluorescing so they would blink in unison. Related to images 3266 and 3268. From a UC San Diego news release, "Researchers create living 'neon signs' composed of millions of glowing bacteria."

Video of high-resolution confocal images depicting vimentin immunofluorescence (green) and nuclei (blue) at the edge of a quail embryo yolk. These images were obtained as part of a study to understand cell migration in embryos. An NIGMS grant to Professor Garcia was used to purchase the confocal microscope that collected these images. Related to images 2807 and 2808.

Model of the mammalian iron enzyme cysteine dioxygenase from a mouse.

The 46 human chromosomes are shown in blue, with the telomeres appearing as white pinpoints. The DNA has already been copied, so each chromosome is actually made up of two identical lengths of DNA, each with its own two telomeres.

Histone proteins loop together with double-stranded DNA to form a structure that resembles beads on a string. See image 2561 for a labeled version of this illustration. Featured in The New Genetics.

Moving protein or other molecules to specific cells to treat or examine them has been a major biological challenge. Scientists have now developed a technique for delivering chemicals to individual cells. The approach involves gold nanowires that, for example, can carry tumor-killing proteins. The advance was possible after researchers developed electric tweezers that could manipulate gold nanowires to help deliver drugs to single cells.

This movie shows the manipulation of the nanowires for drug delivery to a single cell. To learn more about this technique, see this post in the Computing Life series.

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.

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

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 protein N-cadherin, which indicates normal connections between cells. 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 3283.

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

A scanning electron microscope image of an activated mast cell. This image illustrates the interesting topography of the cell membrane, which is populated with receptors. The distribution of receptors may affect cell signaling. This image relates to a July 27, 2009 article in Computing Life.

Glial cells (stained green) in a fruit fly developing embryo have survived thanks to a signaling pathway initiated by neighboring nerve cells (stained red).

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 light organ (~0.5 mm across) of a juvenile Hawaiian bobtail squid, Euprymna scolopes, stained blue. The two pairs of ciliated appendages, or “arms,” on the sides of the organ move Vibrio fischeri bacterial cells closer to the two sets of three pores at the base of the arms that each lead to an interior crypt. This image was taken using a confocal fluorescence microscope.

Related to images 7017, 7018, 7019, and 7020.

A crawling cell with DNA shown in blue and actin filaments, which are a major component of the cytoskeleton, visible in pink. Actin filaments help enable cells to crawl. This image was captured using structured illumination microscopy.

These images show three stages of cell division in Xenopus XL177 cells, which are derived from tadpole epithelial cells. They are (from top): metaphase, anaphase and telophase. The microtubules are green and the chromosomes are blue. Related to 3443.

This photograph of kidney tissue, taken using fluorescent light microscopy, shows a close-up view of part of image 3723. Kidneys filter the blood, removing waste and excessive fluid, which is excreted in urine. The filtration system is made up of components that include glomeruli (for example, the round structure taking up much of the image's center is a glomerulus) and tubules (seen in cross-section here with their inner lining stained green). Related to image 3675 .

Bacillus anthracis (anthrax) cells being killed by a fluorescent trans-translation inhibitor, which disrupts bacterial protein synthesis. The inhibitor is naturally fluorescent and looks blue when it is excited by ultraviolet light in the microscope. This is a color version of Image 3481.

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.

The nucleus contains the DNA of eukaryotic cells. The double membrane that bounds the nucleus flows into the rough endoplasmic reticulum, an organelle studded with ribosomes that manufacture membrane-bound proteins for the rest of the cell.

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.

This image shows mouse fetal heart fibroblast cells. The muscle protein actin is stained red, and the cell nuclei are stained blue. The image was part of a study investigating stem cell-based approaches to repairing tissue damage after a heart attack. Image and caption information courtesy of the California Institute for Regenerative Medicine.

A mouse brain that was genetically modified so that subpopulations of its neurons glow. Researchers often study mice because they share many genes with people and can shed light on biological processes, development, and diseases in humans.

This image was captured using a light sheet microscope.

Related to image 6930 and video 6931.

This illustration shows, in simplified terms, how the CRISPR-Cas9 system can be used as a gene-editing tool. The CRISPR system has two components joined together: a finely tuned targeting device (a small strand of RNA programmed to look for a specific DNA sequence) and a strong cutting device (an enzyme called Cas9 that can cut through a double strand of DNA). This frame (4 out of 4) shows a repaired DNA strand with new genetic material that researchers can introduce, which the cell automatically incorporates into the gap when it repairs the broken DNA.

For an explanation and overview of the CRISPR-Cas9 system, see the iBiology video, and find the full CRIPSR illustration here.

The long, stringy DNA that makes up genes is spooled within chromosomes inside the nucleus of a cell. (Note that a gene would actually be a much longer stretch of DNA than what is shown here.) See image 2539 for an unlabeled 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.

Wound healing requires the action of stem cells. In mice that lack the Sept2/ARTS gene, stem cells involved in wound healing live longer and wounds heal faster and more thoroughly than in normal mice. This confocal microscopy image from a mouse lacking the Sept2/ARTS gene shows a tail wound in the process of healing. Cell nuclei are in blue. Red and orange mark hair follicle stem cells (hair follicle stem cells activate to cause hair regrowth, which indicates healing). See more information in the article in Science.

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.

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.

The extracellular matrix (ECM) is most prevalent in connective tissues but also is present between the stems (axons) of nerve cells, as shown here. Blue-colored nerve cell axons are surrounded by brown-colored, myelin-supplying Schwann cells, which act like insulation around an electrical wire to help speed the transmission of electric nerve impulses down the axon. The ECM is pale pink. The tiny brown spots within it are the collagen fibers that are part of the ECM.

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 2563 for a labeled version of this illustration. Featured in The New Genetics.

This image of the human brain uses colors and shapes to show neurological differences between two people. The blurred front portion of the brain, associated with complex thought, varies most between the individuals. The blue ovals mark areas of basic function that vary relatively little. Visualizations like this one are part of a project to map complex and dynamic information about the human brain, including genes, enzymes, disease states, and anatomy. The brain maps represent collaborations between neuroscientists and experts in math, statistics, computer science, bioinformatics, imaging, and nanotechnology.

This human T cell (blue) is under attack by HIV (yellow), the virus that causes AIDS. The virus specifically targets T cells, which play a critical role in the body's immune response against invaders like bacteria and viruses.

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

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.

This is a magnified view of an Arabidopsis thaliana leaf after several days of infection with the pathogen Hyaloperonospora arabidopsidis. The pathogen's blue hyphae grow throughout the leaf. On the leaf's edges, stalk-like structures called sporangiophores are beginning to mature and will release the pathogen's spores. Inside the leaf, the large, deep blue spots are structures called oopsorangia, also full of spores. Compare this response to that shown in Image 2781. Jeff Dangl has been funded by NIGMS to study the interactions between pathogens and hosts that allow or suppress infection.

Stained kidney tissue. The kidney is an essential organ responsible for disposing wastes from the body and for maintaining healthy ion levels in the blood. It also secretes two hormones, erythropoietin (EPO) and calcitriol (a derivative of vitamin D), into the blood. It works like a purifier by pulling break-down products of metabolism, such as urea and ammonium, from the blood stream for excretion in urine. Related to image 3725.

Speckle microscopy analysis of actin cytoskeleton force. This is an example of NIH-supported research on single-cell analysis. Images in related series; Related to 2799, 2800, 2801, 2802 and 2803.

For fruit flies, the salivary gland is used to secrete materials for making the pupal case, the protective enclosure in which a larva transforms into an adult fly. For scientists, this gland provided one of the earliest glimpses into the genetic differences between individuals within a species. Chromosomes in the cells of these salivary glands replicate thousands of times without dividing, becoming so huge that scientists can easily view them under a microscope and see differences in genetic content between individuals.

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

The long, stringy DNA that makes up genes is spooled within chromosomes inside the nucleus of a cell. (Note that a gene would actually be a much longer stretch of DNA than what is shown here.) See image 2540 for a labeled version of this illustration. Featured in The New Genetics.

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.

The molecules that glow blue in these cultured cells prevent the expression of the mutant proteins that cause Huntington's disease. Biochemist David Corey and others at UT Southwestern Medical Center designed the molecules to specifically target the genetic repeats that code for harmful proteins in people with Huntington's disese. People with Huntington's disease and similar neurodegenerative disorders often have extra copies of a gene segment. Moving from cell cultures to animals will help researchers further explore the potential of their specially crafted molecule to treat brain disorders. In addition to NIGMS, NIH's National Institute of Neurological Disorders and Stroke and National Institute of Biomedical Imaging and Bioengineering also funded this work.

Each of the tiny colored specs in this image is a cell on the surface of a fish scale. To better understand how wounds heal, scientists have inserted genes that make cells brightly glow in different colors into the skin cells of zebrafish, a fish often used in laboratory research. The colors enable the researchers to track each individual cell, for example, as it moves to the location of a cut or scrape over the course of several days. These technicolor fish endowed with glowing skin cells dubbed "skinbow" provide important insight into how tissues recover and regenerate after an injury.

For more information on skinbow fish, see the Biomedical Beat blog post Visualizing Skin Regeneration in Real Time and a press release from Duke University highlighting this research. Related to image 3782.

Disassembly of vasculature and reassembly after addition and then washout of 250 µM TBZ in kdr:GFP frogs. Related to images 3403 and 3404.

A model of the molecule himastatin overlaid on an image of Bacillus subtilis bacteria. Scientists first isolated himastatin from the bacterium Streptomyces himastatinicus, and the molecule shows antibiotic activity. The researchers who created this image developed a new, more concise way to synthesize himastatin so it can be studied more easily. They also tested the effects of himastatin and derivatives of the molecule on B. subtilis.

More information about the research that produced this image can be found in the Science paper “Total synthesis of himastatin” by D’Angelo et al.

Related to image 6848 and video 6851.

Developing fruit fly spermatids require caspase activity (green) for the elimination of unwanted organelles and cytoplasm via apoptosis.

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 lined up.

Related to images 1010, 1011, 1012, 1013, 1014, 1015, 1016, 1017, 1018, and 1019.