A cell in prophase, near the start of mitosis: In the nucleus, chromosomes condense and become visible. In the cytoplasm, the spindle forms. Mitosis is responsible for growth and development, as well as for replacing injured or worn out cells throughout the body. For simplicity, mitosis is illustrated here with only six chromosomes.

These neurons were derived from human embryonic stem cells. The neural cell bodies with axonal projections are visible in red, and the nuclei in blue. Some of the neurons have become dopaminergic neurons (yellow), the type that degenerate in people with Parkinson's disease. Image and caption information courtesy of the California Institute for Regenerative Medicine. Related to images 3270 and 3271.

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.

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.

This image of laboratory-grown cells was taken with the help of a scanning electron microscope, which yields detailed images of cell surfaces.

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

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 2529 for an unlabeled version of this illustration. Featured in Medicines By Design.

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: 1047, 1049, 1050, 1051 and 1052.

Established in 1953, the Coriell Institute for Medical Research distributes cell lines and DNA samples to researchers around the world. Shown here are Coriell's cryogenic tanks filled with liquid nitrogen and millions of vials of frozen cells.

These colorful, computer-generated ribbons show the backbone of a molecule that glows a fluorescent red. The molecule, called mStrawberry, was created by chemists based on a protein found in the ruddy lips of a coral. Scientists use the synthetic molecule and other "fruity" ones like it as a dye to mark and study cell structures.

Map of microtubule growth rates. Rates are color coded. This is an example of NIH-supported research on single-cell analysis. Related to 2798 , 2799, 2801, 2802 and 2803.

Molecular model of the struture of heme. Heme is a small, flat molecule with an iron ion (dark red) at its center. Heme is an essential component of hemoglobin, the protein in blood that carries oxygen throughout our bodies. This image first appeared in the September 2013 issue of Findings Magazine. View side view of heme here 3539.

A spore from the bacterium Bacillus subtilis shows four outer layers that protect the cell from harsh environmental conditions.

The HIV capsid is a pear-shaped structure that is made of proteins the virus needs to mature and become infective. The capsid is inside the virus and delivers the virus' genetic information into a human cell. To better understand how the HIV capsid does this feat, scientists have used computer programs to simulate its assembly. This image shows a series of snapshots of the steps that grow the HIV capsid. A model of a complete capsid is shown on the far right of the image for comparison; the green, blue and red colors indicate different configurations of the capsid protein that make up the capsid “shell.” The bar in the left corner represents a length of 20 nanometers, which is less than a tenth the size of the smallest bacterium. Computer models like this also may be used to reconstruct the assembly of the capsids of other important viruses, such as Ebola or the Zika virus. The studies reporting this research were published in Nature Communications and Nature. To learn more about how researchers used computer simulations to track the assembly of the HIV capsid, see this press release from the University of Chicago.

Dictyostelium discoideum is a microscopic amoeba. A group of 100,000 form a mound as big as a grain of sand. Featured in The New Genetics.

The head of an axolotl—a type of salamander—that has been genetically modified so that its developing nervous system glows purple and its Schwann cell nuclei appear light blue. Schwann cells insulate and provide nutrients to peripheral nerve cells. Researchers often study axolotls for their extensive regenerative abilities. They can regrow tails, limbs, spinal cords, brains, and more. The researcher who took this image focuses on the role of the peripheral nervous system during limb regeneration.

This image was captured using a light sheet microscope.

Related to images 6928 and 6932.

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.

Zika virus is shown in cross section at center left. On the outside, it includes envelope protein (red) and membrane protein (magenta) embedded in a lipid membrane (light purple). Inside, the RNA genome (yellow) is associated with capsid proteins (orange). The viruses are shown interacting with receptors on the cell surface (green) and are surrounded by blood plasma molecules at the top.

The Golgi complex, also called the Golgi apparatus or, simply, the Golgi. This organelle receives newly made proteins and lipids from the ER, puts the finishing touches on them, addresses them, and sends them to their final destinations.

Scientists recently discovered the full molecular structure of telomerase, an enzyme important to aging and cancer. Within each cell, telomerase maintains the telomeres, or end pieces, of a chromosome, preserving genetic data and extending the life of the cell. In their study, a team from UCLA and UC Berkeley found the subunit p50, shown in red, to be a keystone in the enzyme's structure and function. Featured in the May 16, 2013 issue of Biomedical Beat.

These cells are induced stem cells made from human adult skin cells that were genetically reprogrammed to mimic embryonic stem cells. The induced stem cells were made potentially safer by removing the introduced genes and the viral vector used to ferry genes into the cells, a loop of DNA called a plasmid. The work was accomplished by geneticist Junying Yu in the laboratory of James Thomson, a University of Wisconsin-Madison School of Medicine and Public Health professor and the director of regenerative biology for the Morgridge Institute for Research.

A protein called tubulin (green) accumulates in the center of a nucleus (outlined in pink) from an aging cell. Normally, this protein is kept out of the nucleus with the help of gatekeepers known as nuclear pore complexes. But NIGMS-funded researchers found that wear and tear to long-lived components of the complexes eventually lowers the gatekeepers' guard. As a result, cytoplasmic proteins like tubulin gain entry to the nucleus while proteins normally confined to the nucleus seep out. The work suggests that finding ways to stop the leakage could slow the cellular aging process and possibly lead to new therapies for age-related diseases.

Drugs enter different layers of skin via intramuscular, subcutaneous, or transdermal delivery methods. See image 2532 for a labeled version of this illustration. Featured in Medicines By Design.

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.

3D image of Caulobacter bacterium with various components highlighted: cell membranes (red and blue), protein shell (green), protein factories known as ribosomes (yellow), and storage granules (orange).

Crystal structure of the beta2-adrenergic receptor protein. This is the first known structure of a human G protein-coupled receptor, a large family of proteins that control critical bodily functions and the action of about half of today's pharmaceuticals. Featured as one of the November 2007 Protein Structure Initiative Structures of the Month.

The three fibers of the cytoskeleton--microtubules in blue, intermediate filaments in red, and actin in green--play countless roles in the cell.

Motor neuron progenitors (green) were derived from human embryonic stem cells. Image and caption information courtesy of the California Institute for Regenerative Medicine.

A sensor particle being engulfed by a macrophage—an immune cell—and encapsuled in a compartment called a phagosome. The phagosome then fuses with lysosomes—another type of compartment. The left video shows snowman-shaped sensor particles with fluorescent green nanoparticle “heads” and “bodies” colored red by Förster Resonance Energy Transfer (FRET)-donor fluorophores. The middle video visualizes light blue FRET signals that are only generated when the “snowman” sensor—the FRET-donor—fuses with the lysosomes, which are loaded with FRET-acceptors. The right video combines the other two. The videos were captured using epi-fluorescence microscopy.

More details can be found in the paper “Transport motility of phagosomes on actin and microtubules regulates timing and kinetics of their maturation” by Yu et al.

A humorous treatment of the concept of a cycling cell.

Model of an enzyme, PanB, from Mycobacterium tuberculosis, the bacterium that causes most cases of tuberculosis. This enzyme is an attractive drug target.

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: 1047, 1048, 1049, 1050 and 1051.

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

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 2571 and 2572.

The TRPA1 protein is responsible for the burn you feel when you taste a bite of sushi topped with wasabi. Known therefore informally as the "wasabi receptor," this protein forms pores in the membranes of nerve cells that sense tastes or odors. Pungent chemicals like wasabi or mustard oil cause the pores to open, which then triggers a tingling or burn on our tongue. This receptor also produces feelings of pain in response to chemicals produced within our own bodies when our tissues are damaged or inflamed. Researchers used cryo-EM to reveal the structure of the wasabi receptor at a resolution of about 4 angstroms (a credit card is about 8 million angstroms thick). This detailed structure can help scientists understand both how we feel pain and how we can limit it by developing therapies to block the receptor. For more on cryo-EM see the blog post Cryo-Electron Microscopy Reveals Molecules in Ever Greater Detail.

Lab-made liposomes contract where Z rings have gathered together and the constriction forces are greatest (arrows). The top picture shows a liposome, and the bottom picture shows fluorescence from Z rings (arrows) inside the same liposome simultaneously.

Proteins in the neural tissues of this zebrafish embryo direct cells to line up and form the neural tube, which will become the spinal cord and brain. Studies of zebrafish embryonic development may help pinpoint the underlying cause of common neural tube defects--such as spina bifida--which occur in about 1 in 1,000 newborn children.

Superconducting magnet for NMR research, from the February 2003 profile of Dorothee Kern in Findings.

The nucleus of a human fibroblast cell with chromatin—a substance made up of DNA and proteins—shown in various colors. Fibroblasts are one of the most common types of cells in mammalian connective tissue, and they play a key role in wound healing and tissue repair. This image was captured using Stochastic Optical Reconstruction Microscopy (STORM).

Related to images 6888 and 6893.

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.

An atomic force microscopy image shows DNA folded into an intricate, computer-designed structure. The image is featured on Biomedical Beat blog post Cool Images: A Holiday-Themed Collection. For more background on DNA origami, see Cool Image: DNA Origami. See also related image 3690.

Molecular biologists are increasingly relying on bioinformatics software to visualize molecular interaction networks and to integrate these networks with data such as gene expression profiles. Related to 2749.

This image integrates the thousands of known molecular and genetic interactions happening inside our bodies using a computer program called Cytoscape. Images like this are known as network wiring diagrams, but Cytoscape creator Trey Ideker somewhat jokingly calls them "hairballs" because they can be so complicated, intricate and hard to tease apart. Cytoscape comes with tools to help scientists study specific interactions, such as differences between species or between sick and diseased cells. Related to 2737.

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

Scanning electron micrograph of just-divided HeLa cells. Zeiss Merlin HR-SEM. See related images 3519, 3520, 3521, 3522.

Novel biosensor system maps the timing and location of Rac protein activation in a living mouse embryo fibroblast.

Merged fluorescent images of symmetrically (left) or asymmetrically (right) elongating HeLa cells at the end of early anaphase (magenta) and late anaphase (green). Chromosomes and cortical actin are visualized by expressing mCherry-histone H2B and Lifeact-mCherry. Scale bar, 10µm. See the PubMed abstract of this research.

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 cropped image of a white poppy. View poppy uncropped here 3424.

A two-dimensional NMR spectrum of a protein, in this case a 2D 1H-15N HSQC NMR spectrum of a 228 amino acid DNA/RNA-binding protein.