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 video condenses 6.5 minutes into less than a minute to show how the toxin in bee venom, called melittin, destroys an animal or bacterial cell. What looks like a red balloon is an artificial cell filled with red dye. Melittin molecules are colored green and float on the cell's surface like twigs on a pond. As melittin accumulates on the cell's membrane, the membrane expands to accommodate it. In the video, the membrane stretches into a column on the left. When melittin levels reach a critical threshold, countless pinhole leaks burst open in the membrane. The cell's vital fluids (red dye in the video) leak out through these pores. Within minutes, the cell collapses.

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. See more information in the article in Science.

Related to images 3497 and 3500.

Coronaviruses are enveloped viruses responsible for 30 percent of mild respiratory infections and atypical deadly pneumonia in humans worldwide. These deadly pneumonia include those caused by infections with severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). The coronavirus spike glycoprotein mediates virus entry into cells and represents an important therapeutic target. The illustration shows a viral membrane decorated with spike glycoproteins; highlighted in red is a potential neutralization site, which is a protein sequence that might be used as a target for vaccines to combat viruses such as MERS-CoV and other coronaviruses.

Cell division is an incredibly coordinated process. It not only ensures that the new cells formed during this event have a full set of chromosomes, but also that they are endowed with all the cellular materials, including proteins, lipids and small functional compartments called organelles, that are required for normal cell activity. This proper apportioning of essential cell ingredients helps each cell get off to a running start.

This image shows an electron microscopy (EM) thin section taken at 10,000x magnification of a dividing yeast cell over-expressing the protein ubiquitin, which is involved in protein degradation and recycling. The picture features mother and daughter endosome accumulations (small organelles with internal vesicles), a darkly stained vacuole and a dividing nucleus in close contact with a cadre of lipid droplets (unstained spherical bodies).  Other dynamic events are also visible,  such as spindle microtubules in the nucleus and endocytic pits at the plasma membrane.

These extensive details were revealed thanks to a preservation method involving high-pressure freezing, freeze-substitution and Lowicryl HM20 embedding.

This image shows the hierarchical ontology of genes, cellular components and processes derived from large genomic datasets. From Dutkowski et al. A gene ontology inferred from molecular networks Nat Biotechnol. 2013 Jan;31(1):38-45. Related to 3436.

These induced pluripotent stem cells (iPS cells) were derived from a woman's skin. Green and red indicate proteins found in reprogrammed cells but not in skin cells (TRA1-62 and NANOG). These cells can then develop into different cell types. Image and caption information courtesy of the California Institute for Regenerative Medicine. Related to image 3279.

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.

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.

Microscopy image of a tongue. One in a series of two, see image 5810

The center cluster of cells, colored blue, shows a colony of human embryonic stem cells. These cells, which arise at the earliest stages of development, are capable of differentiating into any of the 220 types of cells in the human body and can provide access to cells for basic research and potential therapies. This image is from the lab of the University of Wisconsin-Madison's James Thomson.

The receptor is shown bound to a partial inverse agonist, carazolol.

Featured in the March 15, 2012 issue of Biomedical Beat. Related to Hsp33 Figure 2, image 3355.

In this image, recombinant probes known as FingRs (Fibronectin Intrabodies Generated by mRNA display) were expressed in a cortical neuron, where they attached fluorescent proteins to either PSD95 (green) or Gephyrin (red). PSD-95 is a marker for synaptic strength at excitatory postsynaptic sites, and Gephyrin plays a similar role at inhibitory postsynaptic sites. Thus, using FingRs it is possible to obtain a map of synaptic connections onto a particular neuron in a living cell in real time.

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

This illustration shows, in simplified terms, how the CRISPR-Cas9 system can be used as a gene-editing tool.

Frame 1 shows the two components of the CRISPR system: a strong cutting device (an enzyme called Cas9 that can cut through a double strand of DNA), and a finely tuned targeting device (a small strand of RNA programmed to look for a specific DNA sequence).

In frame 2, the CRISPR machine locates the target DNA sequence once inserted into a cell.

In frame 3, the Cas9 enzyme cuts both strands of the DNA.

Frame 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.

Download the individual frames: Frame 1, Frame 2, Frame 3, and Frame 4.

The photo shows a confocal microscopy image of perineuronal nets (PNNs), which are specialized extracellular matrix (ECM) structures in the brain. The PNN surrounds some nerve cells in brain regions including the cortex, hippocampus and thalamus. Researchers study the PNN to investigate their involvement stabilizing the extracellular environment and forming nets around nerve cells and synapses in the brain. Abnormalities in the PNNs have been linked to a variety of disorders, including epilepsy and schizophrenia, and they limit a process called neural plasticity in which new nerve connections are formed. To visualize the PNNs, researchers labeled them with Wisteria floribunda agglutinin (WFA)-fluorescein. Related to image 3741.

Haplotypes are combinations of gene variants that are likely to be inherited together within the same chromosomal region. In this example, an original haplotype (top) evolved over time to create three newer haplotypes that each differ by a few nucleotides (red). See image 2567 for a labeled version of this illustration. Featured in The New Genetics.

This is an adult flowering Arabidopsis thaliana plant with the inbred designation L-er. Arabidopsis is the most widely used model organism for researchers who study plant genetics.

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

What looks like the gossamer wings of a butterfly is actually the retina of a mouse, delicately snipped to lay flat and sparkling with fluorescent molecules. The image is from a research project investigating the promise of gene therapy for glaucoma. It was created at an NIGMS-funded advanced microscopy facility that develops technology for imaging across many scales, from whole organisms to cells to individual molecules.

The ability to obtain high-resolution imaging of tissue as large as whole mouse retinas was made possible by a technique called large-scale mosaic confocal microscopy, which was pioneered by the NIGMS-funded National Center for Microscopy and Imaging Research. The technique is similar to Google Earth in that it computationally stitches together many small, high-resolution images.

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.

Disassembly of vasculature in kdr:GFP frogs following addition of 250 µM TBZ. Related to images 3404 and 3505.

If a picture is worth a thousand words, what's a movie worth? For researchers studying cell migration, a "documentary" of fruit fly cells (bright green) traversing an egg chamber could answer longstanding questions about cell movement. Historically, researchers have been unable to watch this cell migration unfold in living ovarian tissue in real time. But by developing a culture medium that allows fly eggs to survive outside their ovarian homes, scientists can observe the nuances of cell migration as it happens. Such details may shed light on how immune cells move to a wound and why cancer cells spread to other sites. See 3594 for still image.

These developing mouse nerve cells have a nucleus (yellow) surrounded by a cell body, with long extensions called axons and thin branching structures called dendrites. Electrical signals travel from the axon of one cell to the dendrites of another.

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

The chemical structure of the morphine molecule

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

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

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.

A cell nucleus (blue) surrounded by lipid droplets (yellow). Exogenously expressed, S-tagged UBXD8 (green) recruits endogenous p97/VCP (red) to the surface of lipid droplets in oleate-treated HeLa cells. Nucleus stained with DAPI.

The feeding tube, or pharynx, of a planarian worm with cilia shown in red and muscle fibers shown in green

Trajectories of single molecule labeled cell surface receptors. This is an example of NIH-supported research on single-cell analysis. Related to 2798 , 2799, 2800, 2802 and 2803.

This network map shows molecular interactions (yellow) associated with a congenital condition that causes heart arrhythmias and the targets for drugs that alter these interactions (red and blue).

Model of aspartoacylase, a human enzyme involved in brain metabolism.

The cone cell of the eye allows you to see in color. Appears in the NIGMS booklet Inside the Cell.

Model of the enzyme aminopeptidase N from the human pathogen Neisseria meningitidis, which can cause meningitis epidemics. The structure provides insight on the active site of this important molecule.

This color-enhanced image is a scanning electron microscope image of retinal pigment epithelial (RPE) cells derived from human embryonic stem cells. The cells are remarkably similar to normal RPE cells, growing in a hexagonal shape in a single, well-defined layer. This kind of retinal cell is responsible for macular degeneration, the most common cause of blindness. Image and caption information courtesy of the California Institute for Regenerative Medicine. Related to image 3287.

By attaching fluorescent proteins to the genetic circuit responsible for B. subtilis's stress response, researchers can observe the cells' pulses as green flashes. In response to a stressful environment like one lacking food, B. subtilis activates a large set of genes that help it respond to the hardship. Instead of leaving those genes on as previously thought, researchers discovered that the bacteria flip the genes on and off, increasing the frequency of these pulses with increasing stress. See entry 3254 for the related video.

Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. Typical circadian rhythms lead to high energy during the middle of the day (10 a.m. to 1 p.m.) and an afternoon slump. At night, circadian rhythms cause the hormone melatonin to rise, making a person sleepy.

Learn more in NIGMS’ circadian rhythms featured topics page.

See 6612 for the Spanish version of this infographic.

Telophase during mitosis: Nuclear membranes form around each of the two sets of chromosomes, the chromosomes begin to spread out, and the spindle begins to break down. 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.

An adult Hawaiian bobtail squid, Euprymna scolopes, (~4 cm) surrounded by newly hatched juveniles (~2 mm) in a bowl of seawater.

Related to image 7011 and video 7012.

The white circle in this image is a Petri dish, named for its inventor, Julius Richard Petri. These dishes are one of the most common pieces of equipment in biology labs, where researchers use them to grow cells.

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

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.

Stanford University scientist Vijay Pande decided to couple the power of computers with the help of the public. He initiated a project called Folding@Home, a so-called distributed computing project in which anyone who wants to can download a screensaver that performs protein-folding calculations when a computer is not in use. Folding@Home is modeled on a similar project called SETI@Home, which is used to search for extraterrestrial intelligence.

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.

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 6887 and 6893.

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.

The endoplasmic reticulum comes in two types: Rough ER is covered with ribosomes and prepares newly made proteins; smooth ER specializes in making lipids and breaking down toxic molecules.

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.