A Trigonium diatom imaged by a quantitative orientation-independent differential interference contrast (OI-DIC) microscope. Diatoms are single-celled photosynthetic algae with mineralized cell walls that contain silica and provide protection and support. These organisms form an important part of the plankton at the base of the marine and freshwater food chains. The width of this image is 90 μm.

More information about the microscopy that produced this image can be found in the Journal of Microscopy paper “An Orientation-Independent DIC Microscope Allows High Resolution Imaging of Epithelial Cell Migration and Wound Healing in a Cnidarian Model” by Malamy and Shribak.

This image captures the many layers of nerve cells in the retina. The top layer (green) is made up of cells called photoreceptors that convert light into electrical signals to relay to the brain. The two best-known types of photoreceptor cells are rod- and cone-shaped. Rods help us see under low-light conditions but can't help us distinguish colors. Cones don't function well in the dark but allow us to see vibrant colors in daylight.

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

Multiphoton fluorescence image of HeLa cells with cytoskeletal microtubules (magenta) and DNA (cyan). Nikon RTS2000MP custom laser scanning microscope. See related images 3518, 3519, 3521, 3522.

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.

This image captures the spiral-shaped ovary of an anglerfish in cross-section. Once matured, these eggs will be released in a gelatinous, floating mass. For some species of anglerfish, this egg mass can be up to 3 feet long and include nearly 200,000 eggs.

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

Cdc42, a member of the Rho family of small guanosine triphosphatase (GTPase) proteins, regulates multiple cell functions, including motility, proliferation, apoptosis, and cell morphology. In order to fulfill these diverse roles, the timing and location of Cdc42 activation must be tightly controlled. Klaus Hahn and his research group use special dyes designed to report protein conformational changes and interactions, here in living neutrophil cells. Warmer colors in this image indicate higher levels of activation. Cdc42 looks to be activated at cell protrusions.

Related to images 2451, 2453, and 2454.

Like a group of barnacles hanging onto a rock, these human cells hang onto a matrix coated glass slide. Actin stress fibers, stained magenta, and the protein vinculin, stained green, make this adhesion possible. The fibroblast nuclei are stained blue.

Two healthy cells (bottom, left) enter into apoptosis (bottom, center) but spring back to life after a fatal toxin is removed (bottom, right; top).

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.

Multicellular yeast called snowflake yeast that researchers created through many generations of directed evolution from unicellular yeast. Stained cell membranes (green) and cell walls (red) reveal the connections between cells. Younger cells take up more cell membrane stain, while older cells take up more cell wall stain, leading to the color differences seen here. This image was captured using spinning disk confocal microscopy.

Related to images 6970 and 6971.

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

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.

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.

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.

Related to images 1010, 1011, 1013, 1014, 1015, 1016, 1017, 1018, 1019, and 1021.

Bean-shaped mitochondria are cells' power plants. These organelles have their own DNA and replicate independently. The highly folded inner membranes are the site of energy generation.

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.

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.

This image shows the structure of a synapse, or junction between two nerve cells in three dimensions. From the brain of a mouse.

Cross-section of skin anatomy shows layers and different tissue types.

In the absence of the engulfment receptor Draper, salivary gland cells (light blue) persist in the thorax of a developing Drosophila melanogaster pupa. See image 2758 for a cross section of a normal pupa that does express Draper.

A zebrafish embryo showing its natural colors. Zebrafish have see-through eggs and embryos, making them ideal research organisms for studying the earliest stages of development. This image was taken in transmitted light under a polychromatic polarizing microscope.

This image shows the extracellular matrix (ECM) on the surface of a soleus (lower calf) muscle in light brown and blood vessels in pink. Near the bottom of the photo, a vessel is opened up to reveal red blood cells. Scientists know less about the ECM in muscle than in other tissues, but it's increasingly clear that the ECM is critical to muscle function, and disruption of the ECM has been associated with many muscle disorders. The ECM in muscles stores and releases growth factors, suggesting that it might play a role in cellular communication.

The cerebellum is the brain's locomotion control center. Found at the base of your brain, the cerebellum is a single layer of tissue with deep folds like an accordion. People with damage to this region of the brain often have difficulty with balance, coordination and fine motor skills.

This image of a mouse cerebellum is part of a collection of such images in different colors and at different levels of magnification from the National Center for Microscopy and Imaging Research (NCMIR). Related to image 5800.

Influenza (flu) virus proteins in the act of self-replication. Viral nucleoprotein (blue) encapsidates [encapsulates] the RNA genome (green). The influenza virus polymerase (orange) reads and copies the RNA genome. In the background is an image of influenza virus ribonucleoprotein complexes observed using cryo-electron microscopy. This image is from a November 2012 News Release.

Microscopy image of tongue. One in a series of two, see image 5811

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.

Meiosis is used to make sperm and egg cells. During meiosis, a cell's chromosomes are copied once, but the cell divides twice. During mitosis, the chromosomes are copied once, and the cell divides once. For simplicity, cells are illustrated with only three pairs of chromosomes.

See image 1333 for an unlabeled version of this illustration.

Insects like the fruit fly use an elaborate network of branching tubes called trachea (green) to transport oxygen throughout their bodies. Fruit flies have been used in biomedical research for more than 100 years and remain one of the most frequently studied model organisms. They have a large percentage of genes in common with us, including hundreds of genes that are associated with human diseases.

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

The plasma membrane is a cell's protective barrier. See image 2523 for an unlabeled version of this illustration. Featured in The Chemistry of Health.

Cell-like compartments that spontaneously emerged from scrambled frog eggs, with nuclei (blue) from frog sperm. Endoplasmic reticulum (red) and microtubules (green) are also visible. Image created using confocal microscopy.

For more photos of cell-like compartments from frog eggs view: 6584, 6585, 6586, 6591, 6592.

For videos of cell-like compartments from frog eggs view: 6587, 6588, 6589, and 6590.

This image shows a cell in two stages of division: prometaphase (top) and metaphase (bottom). To form identical daughter cells, chromosome pairs (blue) separate via the attachment of microtubules made up of tubulin proteins (pink) to specialized structures on centromeres (green).

Here, a human HeLa cell (a type of immortal cell line used in laboratory experiments) is undergoing cell division. They come from cervical cancer cells that were obtained in 1951 from Henrietta Lacks, a patient at the Johns Hopkins Hospital. The final stage of division, called cytokinesis, occurs after the genomes—shown in yellow—have split into two new daughter cells. The myosin II is a motor protein shown in blue, and the actin filaments, which are types of protein that support cell structure, are shown in red.

Floral pattern emerging as two bacterial species, motile Acinetobacter baylyi (red) and non-motile Escherichia coli (green), are grown together for 48 hours on 1% agar surface from a small inoculum in the center of a Petri dish.

See 6557 for a photo of this process at 24 hours on 0.75% agar surface.
See 6553 for another photo of this process at 48 hours on 1% agar surface.
See 6556 for a photo of this process at 72 hours on 0.5% agar surface.
See 6550 for a video of this process.

Individual cells are color-coded based on their identity and signaling activity using a protein circuit technology developed by the Coyle Lab. Just as a radio allows you to listen to an individual frequency, this technology allows researchers to tune into the specific “radio station” of each cell through genetically encoded proteins from a bacterial system called MinDE. The proteins generate an oscillating fluorescent signal that transmits information about cell shape, state, and identity that can be decoded using digital signal processing tools originally designed for telecommunications. The approach allows researchers to look at the dynamics of a single cell in the presence of many other cells.

Related to video 7022.

These microscopic roundworms, called Caenorhabditis elegans, lack eyes and the opsin proteins used by visual systems to detect colors. However, researchers found that the worms can still sense the color of light in a way that enables them to avoid pigmented toxins made by bacteria. This image was captured using a stereo microscope.

Cells move forward with lamellipodia and filopodia supported by networks and bundles of actin filaments. Proper, controlled cell movement is a complex process. Recent research has shown that an actin-polymerizing factor called the Arp2/3 complex is the key component of the actin polymerization engine that drives amoeboid cell motility. ARPC3, a component of the Arp2/3 complex, plays a critical role in actin nucleation. In this photo, the ARPC3-/- fibroblast cells were fixed and stained with Alexa 546 phalloidin for F-actin (red), mDia1 (green), and DAPI to visualize the nucleus (blue). In ARPC3-/- fibroblast cells, mDia1 is localized at the tips of the filopodia-like structures. Related to images 3328, 3329, 3330, 3332, and 3333.

This skyline of New York City was created by “printing” nanodroplets containing yeast (Saccharomyces cerevisiae) onto a large plate. Each dot is a separate yeast colony. As the colonies grew, a picture emerged, creating art. To make the different colors shown here, yeast strains were genetically engineered to produce pigments naturally made by bacteria, fungi, and sea creatures such as coral and sea anemones. Using genes from other organisms to make biological compounds paves the way toward harnessing yeast in the production of other useful molecules, from food to fuels and drugs.

This is a fibroblast, a connective tissue cell that plays an important role in wound healing. Normal fibroblasts have smooth edges. In contrast, this spiky cell is missing a protein that is necessary for proper construction of the cell's skeleton. Its jagged shape makes it impossible for the cell to move normally. In addition to compromising wound healing, abnormal cell movement can lead to birth defects, faulty immune function, and other health problems.

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

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.

The image is from a figure in an article published in the journal eLife. There is an annotated version of this graphic at 5760.

The largest human cell (by volume) is the egg. Human eggs are 150 micrometers in diameter and you can just barely see one with a naked eye. In comparison, consider the eggs of chickens...or ostriches!

Many disease-causing microbes manipulate their host’s metabolism and cells for their own ends. Microsporidia—which are parasites closely related to fungi—infect and multiply inside animal cells, and take the rearranging of cells’ interiors to a new level. They reprogram animal cells such that the cells start to fuse, causing them to form long, continuous tubes. As shown in this image of the roundworm Caenorhabditis elegans, microsporidia (dark oval shapes) invaded the worm’s gut cells (long tube; the cell nuclei are shown in red) and have instructed the cells to merge. The cell fusion enables the microsporidia to thrive and propagate in the expanded space. Scientists study microsporidia in worms to gain more insight into how these parasites manipulate their host cells. This knowledge might help researchers devise strategies to prevent or treat infections with microsporidia.

For more on the research into microsporidia, see this news release from the University of California San Diego. Related to images 5777 and 5779.

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

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 neural crest cell-derived, migrating pigment cells in a salamander. 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, 5756 and 5757.

A 20-µm thick section of mouse midbrain. The nerve cells are transparent and weren’t stained. Instead, the color is generated by interaction of white polarized light with the molecules in the cells and indicates their orientation.

The image was obtained with a polychromatic polarizing microscope that shows the polychromatic birefringent image with hue corresponding to the slow axis orientation. More information about the microscopy that produced this image can be found in the Scientific Reports paper “Polychromatic Polarization Microscope: Bringing Colors to a Colorless World” by Shribak.

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.

These smooth muscle cells were derived from mouse neural crest stem cells. Red indicates smooth muscle proteins, blue indicates nuclei. Image and caption information courtesy of the California Institute for Regenerative Medicine.

Nerve cells have long, invisibly thin fibers that carry electrical impulses throughout the body. Some of these fibers extend about 3 feet from the spinal cord to the toes.

Human cells with the gene that codes for the protein FIT2 deleted. After an experimental intervention, they are expressing a nonfunctional version of FIT2, shown in green. The lack of functional FIT2 affected the structure of the endoplasmic reticulum (ER), and the nonfunctional protein clustered in ER membrane aggregates, seen as large bright-green spots. Lipid droplets are shown in red, and the nucleus is visible in gray. This image was captured using a confocal microscope. Related to image 6773.

Flower development is a carefully orchestrated, genetically programmed process that ensures that the male (stamen) and female (pistil) organs form in the right place and at the right time in the flower. In this image of young Arabidopsis flower buds, the gene SUPERMAN (red) is activated at the boundary between the cells destined to form the male and female parts. SUPERMAN activity prevents the central cells, which will ultimately become the female pistil, from activating the gene APETALA3 (green), which induces formation of male flower organs. The goal of this research is to find out how plants maintain cells (called stem cells) that have the potential to develop into any type of cell and how genetic and environmental factors cause stem cells to develop and specialize into different cell types. This work informs future studies in agriculture, medicine and other fields.