Specimens featured in the fluorescence digital image gallery are derived from a combination of stained thin sections, whole mounts, suspensions, smears, and several additional mounting techniques. Stained tissue culture cells and thin sections were labeled with either fluorescent dyes or common histology stains such as eosin, fast green, and safranin. Fluorescence microscopy and photomicrography was conducted by Charles D. Howard. Background research for the figure captions was provided by Elise Sessions. Kathleen Carr supervised the authoring and assembly of text for each of the gallery entries.

Alfalfa Root - Alfalfa, or Medicago sativa, is a deep-rooted perennial native to the Mediterranean region near Iran but which also grows well in North America and Western Asia. Also called Lucerne, or Purple Medic, it looks very much like clover with a smooth, erect stem growing 2-3 feet tall, grayish-green feathery trifoliate leaves, and egg-shaped leaflets. It is tolerant of a wide range of climatic conditions and can be grown in cool, humid environments as well as irrigated arid regions.

American Dog Tick - Two of the three families of ticks are capable of transmitting diseases to humans: Ixodidae, or hard ticks, and Argasidae, or soft ticks. The photomicrograph presented here is a close-up view of the piercing mouthparts from Dermacentor variabilis, commonly known as the American dog tick.

Ants (Formicidae) - Ants are one of the most successful groups of insects to inhabit the Earth during the past 100 million years. All ants belong to the insect family Formicidae in the order Hymenoptera, the same order comprising bees and wasps, and are believed to have descended from a wasp-like ancestor. Scientists have classified 252 living genera of ants.

Antelope Hair - Antelopes are even-toed ruminants belonging to the family Bovidae, order Artiodactyla. This family includes bison, buffalo, cattle, sheep and goats. Antelopes are herbivores, native to Africa and parts of Asia. Pronghorn antelopes, which belong to the family Antilocapridae, are native to North America, but aren't true antelopes because they annually shed the outer sheath of their branched horns unlike other antelope species.

Basswood Stem - Basswood seeds and twigs are a popular food for wildlife and the flowers smell and taste like honey, attracting over 60 insect pollinators, especially honey bees. The soft, light-colored wood has an even grain, long favored by wood carvers. Native Americans used the fibrous inner bark to make rope, which was used to bind wounds and stitch mats made from cattail leaves.

Bed Bugs (Cimex lectularius) - Bed bugs feed primarily on human blood, but can be found on bats, rabbits, domestic animals, and other warm-blooded mammals. They also have the ability to survive long periods of starvation and adverse temperatures. Bed bugs are mentioned in early European history and literature and are believed to have been transported around the world by clothing and bedding. Today, they are found in both temperate and tropical regions.

Bird Lungs - At rest, a bird's oxygen consumption rate is higher than all other vertebrates. That rate is even higher when engaging in activities such as flying. Birds are capable of high rates of gas exchange because of the special construction of their lungs, and additional breathing organs, a complex series of air sacs.

Bird Skin - Birds have a thin and delicate epidermis, or skin, compared to other vertebrates. Their skin produces specialized structures called feathers, which is one of the unique characteristics of birds. Feathers are made up of keratin, a flexible protein that also forms the hair and fingernails of mammals. Thick epidermal scales, like those found in reptiles, usually cover exposed areas of skin, such as the legs and feet.

Black Grape Rot - Black rot, caused by the fungus Guignardia bidwellii is one of the most serious diseases of cultivated grapes in the eastern United States, especially in warm, humid areas.

Cactus - Cactus plants are perennial succulents native to the Americas and easily grown in almost all warm and arid climates around the world. The ability to sustain extreme temperatures makes them one of the heartiest plants on earth. Thorns, hairs, and layers of wax are some of the characteristics of cactuses that help to maintain their core temperature.

Corn Grain - Corn is the common name for the cereal grass widely grown as food for humans and animals. Along with wheat and rice, it is one of the world's chief grain crops and the largest crop grown in the USA. Native to the Americas, corn (Zea mays) is the domesticated variety of the Zea grass family, originally was cultivated by Native Americans 8,000 to 10,000 years ago.

Corn Smut - Smut is a disease of cereals, corn, grasses, onions, and sorghum that can be caused by any of more than 700 species of parasitic fungi. Smuts generally have a negative economic impact on agriculture, because they affect so many food crops. An exception to this is corn smut, which is considered a delicacy in Mexico.

Dutchman's Pipe - A native of central and eastern North America, Dutchman's pipe, Aristolochia durior, is a climbing vine and part of the birthwort family. The vine is planted often as a screen or cultivated as a porch vine because it is easy and quick to grow. It is distinguished by its large heart-shaped leaves and yellowish or purplish tubular flowers that resemble traditional Meerschaum smoking pipes.

Elderberry (Sambucus canadensis) - About 30 species of Elderberry make up the genus Sambucus of the family Caprifoliaceae. Elderberry bushes can be found in most forested temperate or subtropical areas around the world. In horticulture, the bushes are often used as garden shrubs and are well known for their fruit, which is used to make wines, syrups, cordial, jellies, pies and also serves as a source of food for wildlife.

Fava Bean Root Tip Mitosis - The fava bean plant (Vicia faba) also known as broad bean or horse bean, is a legume belonging to the pea family, Fabaceae. It is cultivated for its seeds, six to eight beans resembling large round limas, packed inside a large, pale-green, velvety pod.

Female Pine Cones - Female pine cones are generally found in the upper branches of the tree crown, above the male cone. This reduces the possibility of self-fertilization by the wind-borne male gametes.

Fern Spores - Fern is a common name for the cryptogamous (spore-producing) plants belonging to the division Filicophyta, also called Filicinophyta. They are primitive vascular plants with true roots, stems, and complex leaves. Most ferns reproduce through the alternation of generations, alternating successive generations of sexual and asexual forms.

Fish Gill Filaments - Fish gotta swim but they gotta breathe too. Unlike land vertebrates or marine mammals, they don't have lungs, but they do have paired respiratory structures called gills, also called branchia. The photomicrograph in this section illustrates a stained thin section of fish gill imaged using fluorescence illumination and fluorite optics.

Fleas - Ctenocephalides felis is commonly known as the cat flea and Ctenocephalides canis is known as the dog flea. Both are members of the 1,600 species referred to as fleas, order Siphonaptera ("wingless siphon"). These blood-sucking insects can be found worldwide, from the Arctic to the tropics.

Guinea Pig Hair - The guinea pig (Cavia porcellus) is a domesticated form of the cavy and is native to in South America. It is believed to have been domesticated during pre-Incan times from a wild species that lived in Peru. It is not, in fact, a pig but is a rodent, a relative of mice, rats and hamsters.

Head Louse - There are three species of louse that parasitize humans: the head louse (Pediculus humanus capitis); the body louse, better known as the cootie (P. humanus humanus); and the crab, or pubic, louse (Phthirus pubis). These species belong to the insect order Anoplura and have long been associated with people. Archaeologists have even found louse combs buried with Egyptian mummies, who were apparently anticipating head lice in the afterlife.

Honey Bee Leg - Honeybees are classified in any of the four species that belong to the genus Apis. They are classified, along with 20,000 other insect species, as members of the Apoidea superfamily (order Hymenoptera), which includes ants, wasps, hornets, and many other species of bees.

Honey Bee Stinger - The honeybee's stinger is smaller than the head of a pin, but its venom can produce pain worse than a hypodermic needle. It's even worse for the two of every one hundred people who are allergic to bee venom, resulting in swelling, rash, dizziness, and even anaphylactic shock.

House Fly Face - The often maligned common house fly is generally thought to be a nuisance and vector for many diseases that affect both humans and animals. Flies lay up to 1000 eggs in some of the most undesirable settings such as garbage, decomposing plant and animal matter, feces, spoiled food, and manure. Although more abundant in the warm spring and hot summer weather, house flies may exist year-round in temperate climates, where their life cycles occur every eight days.

House Fly Mouth - A closer view of the house fly face, this time peering deep into the insect's mouth. Although some flies can bite, the house fly can't. Its mouthparts are made of soft, spongy mouthparts called the labella and proboscis. The labella gently dab liquids into its proboscis, which then sucks up the liquid. If the fly encounters solid food it wants to eat, it drops saliva onto it, turning the food into a liquid.

Human Flea - Pulex irritans, the human flea, is one of more than 1,600 species and subspecies of fleas that populate the Earth from the Arctic Circle to the deserts of Africa. Fleas belong to the insect order Siphonaptera and parasitize mammals and birds for their blood, using specialized anatomical structures to attach to the hosts' skin.

Human Hyaline Cartilage - Cartilage is a dense network of collagen fibers, embedded in a firm but plastic-like gelatinous substance, covered by a membrane called the perichondrium. Mammals have three types of cartilage: hyaline, elastic, and fibrocartilage.

Human Roundworm - Ascaris lumbricoides, the large human roundworm, is the most massive nematode to parasitize humans, growing up to 16 inches (40 centimeters) long and often as thick as a pencil. Infections of this intestinal roundworm, called ascariasis, are extremely common in rural communities around the world and affect as many as 1.5 billion people, almost one-quarter of the world's population.

Human Scalp - In humans, the scalp is a specialized area of skin on top of the head, usually covered with hair in both sexes. It consists of three layers: a layer of skin, an underlying layer of tissue and blood vessels, and the occipitofrontalis muscle, which raises the eyebrows, stretching from the top of the eyebrows to the back of the head.

Human Spinal Cord - The human nervous system carries stimuli from sensory receptors to the brain by two main parts: the central nervous system and the peripheral nervous system. The brain and spinal cord make up the central nervous system. The spinal cord represents the major nerve track in all vertebrates.

Japanese Pony Belly Hair - Japanese ponies are particularly famous for their hair. Its soft and luxurious feel to the skin has made Japanese pony hair a favorite in the world of cosmetics, used for powder brushes and other face brushes. Recently the pony hair market has expanded to include clothing, shoes and even toys.

Kapok Fiber - Kapok fiber is a silky cotton-like substance that surrounds the seeds in the pods of the ceiba tree. The ceiba tree belongs to the Bombacacae family and is primarily found in Asia in tropical and semi-tropical climates, at an altitude less than 1000 feet (304 meters), in porous volcanic soil.

Leeches - Leech is a common name for over 650 species of carnivorous, bloodsucking annelid worms that make up the class Hirudinea of the phylum Annelida. They are equipped with a large and a small sucker. The mouth is located on the small sucker and has three jaws with sharp teeth that make a y-shaped incision in the flesh.

Lily Flower Bud - The lily is an herbaceous flowering plant native to the temperate areas of the Northern Hemisphere. The name, lily, is most frequently applied to the 80-100 species belonging to the genus Lilium of the family Liliaceae.

Lone Star Tick - Amblyomma americanum is commonly known as the Lone Star tick. It's named for the dramatic iridescent spot that can be found on the female. Lone star ticks are found primarily in northern and central Florida, but can also be found in the mid-Atlantic and south-central parts of the United States, as well as Mexico.

Mammalian Compact Bones - There are two basic structural types of bone in mammals, compact and spongy. Compact bone is very dense and hard on the outside, and makes up most of the bones in the arms and legs. The structural units are osteons, which are elongated cylinders acting as weight-bearing pillars that can withstand high levels of mechanical stress.

Mammalian Spongy Bone - Spongy bone, also known as cancellous bone, is less dense than compact bone and is composed of a honeycomb-like network of bones called trabeculae. Spongy bone actually looks like a sponge. It is found at the expanded heads of long bones, such as bones of the arms, legs, fingers and toes.

Milkweed Fibers - Milkweed is a perennial plant whose species are native primarily to North America. It can be found growing in prairies, pastures, along roadsides and on the banks or edges of ponds and lakes. As suggested by its name, milkweed contains an abundance of milky sap in its leaves, stems and pods. A healthy plant can reach nearly 5 feet, thriving in full to partial sun in all types of soil.

Mites - There are over 20,000 species of mites, tiny anthropod invertebrates belonging to the class Arachnida. Along with the tick, they make up the order Acarina. Mites can be found worldwide in diverse habitats, including brackish water, fresh water, hot springs, soil, plants, and mosses as well as upon and inside animals. Parasitic forms may live in the nasal passages, lungs, stomach, or even deeper body tissues.

Moss Reproductive Tissue - Mosses are the most common, diverse, and advanced group of Bryophytes, a division of green, seedless plants that dates back to the Permian period (286 to 245 million years ago). In Bryophytes, the antheridium is the female sex organ, which produces eggs. The archegonium, illustrated along with the antheridium in the fluorescence photomicrograph presented below, is the male reproductive organ, which produces sperm.

Mouse Intestines - Mouse intestines are very much like those of other vertebrate animals. The large intestine is wider and shorter than the small intestine and its primary function is to absorb water and electrolytes from digestive residues and store fecal matter.

Mouse Kidney - The kidney is an organ that maintains water balance and expels metabolic wastes in vertebrates and some invertebrates. Primitive and embryonic kidneys have sets of specialized tubules that empty into two collecting ducts that pass urine into a primitive bladder. The more advanced mammalian kidney is a paired compact organ with functional units, called nephrons, that filter the blood, reabsorbing water and nutrients and secreting wastes, producing the final urine.

Mycorrhizal Fungi - Most plant species are better able to utilize the soil in which they're growing with the help of beneficial microorganisms called mycorrhizal fungi. These fungi live in symbiosis with plants, growing on the surface of their roots (ectotrophic) or actually invading the hosts' roots (endotrophic).

Obelia Hydroid: First Generation - Obelia belongs to the phylum Cnidaria, which includes corals, sea anemones, jellyfish, and the freshwater hydra. The many species of this genus are widely distributed throughout all the oceans and are typical of cnidarians, both in their morphology and their life cycle.

Oleander Leaf - Oleander, Nerium oleander, is an ornamental evergreen that belongs to the dogbane family, Apocynaceae. The best-known oleander shrub, called rosebay, is native to the Mediterranean and Middle East regions and is distinguished by dark green leaves that are thick, leathery, and lance-like.

Peach Brown Rot Fungus - Peach Brown Rot is a serious disease of fruit trees caused by the fungus Monilinia fructicola. Also affected by this devastating fungus are other stone fruits such as cherries, plums, prunes, nectarines, and apricots.

Peach Leaf Curl - Peach leaf curl is a common disease of peach and nectarine trees caused by the fungus Taphrina deformans. Spores of the fungus overwinter on the surface of peach twigs. In spring, the spores multiply during periods of moist weather until the leaf buds swell and open.

Pine Root - The root system is the part of a plant that normally grows underground. Its primary functions are anchorage of the plant, absorption of water and dissolved minerals, conduction of these to the stem, and storage of reserve foods. Gymnosperms, such as pine trees, have a taproot system. A primary root, or taproot, emerges from the seedling and secondary roots grow laterally from it. The taproot grows deep into the ground, enabling the tree to withstand long periods of drought.

Pine Tree Pollen - Pine trees are gymnosperms, nonflowering plants that produce exposed seeds not enclosed in an ovary. They are monoecious, bearing gametes of both sexes on the same tree. These gametes are housed in a structure called a strobilus, or cone.

Pine Wood - Pine is the common name for species belonging to the genus Pinus, a member of the family Pinaceae, resinous trees with needle-like leaves. Consisting of about 262 species, this is the largest family of conifers and includes fir, larch, spruce, hemlock, cedar and Douglas fir.

Privet Leaf - About 50 species of privet shrubs and small trees belong to the genus Ligustrum of the Olive family, Oleaceae. They are popularly used as hedges and screens. Privets are native to Europe, Asia, and the Mediterranean regions.

Raw Meat - The tissue structure of raw meat is revealed in this fluorescence photomicrograph of a stained thin section of ground hamburger. As evidenced by this micrograph, combining fluorescence microscopy with classical histological staining techniques often yields enhancement of cellular features.

Rhizopus Rot - Rhizopus rot is a soft rot of harvested or over-ripe stone fruits, such as peaches, nectarines, sweet cherries, and plums. Mold species belonging to the genus Rhizopus cause the rot, which initially appears on the fruit as a fuzzy white mass, called the mycelium.

Snail Radula - Snails belong to the class Gastropoda, the largest group of the mollusk phylum. The most recent estimate of the number of known gastropod species is 37,500. Although gastropods are common in marine and freshwater habitats, they are the only mollusks to flourish on land.

Sweet Flag Grass - Sweet flag, Acorus calamus, is a grass-like perennial that can grow up to 2 meters or 6.6 feet high. Sweet flag, along with the common cattail, thrives in wet areas like the edges of streams, ponds, and lakes. The thick, erect leaves resemble an iris. The flowers are greenish brown cylinders covered in little rounded spikes, but they rarely flower.

Tilia Stem - The American Basswood, Tilia americana, is a treasured hardwood tree of the Eastern and Central United States. It has a tall, straight trunk and rounded crown that provides excellent shade during the hot summer months.

Trichina Worm - Trichina (Trichinella spiralis) is a parasitic nematode worm that causes trichinosis, a serious disease in humans and other meat-eating mammals. A member of the phylum Aschelminthes, it ranges in length from 0.06 to 0.2 inches (1.5 to 4 millimeters) and has a nearly worldwide distribution.

Wheat - Wheat is the common name for any of the cereal grasses belonging to the genus Triticum and is an important food source for people around the world. Evidence shows that wheat grew as a wild grass in the Middle East nearly 10,000 years ago and was in cultivation by 6,000 BC.

Wheat Kernel - Wheat grains can be eaten by simply soaking and cooking the grain. The majority of food uses, however, require more processing. First, the grain is cleaned and conditioned by adding water. This causes the kernel to break up properly when it is milled. During the milling process, the grain is cracked, then flattened by rollers. This process continues and particles are sifted by size until about 70 percent of the grain has been powdered into flour.

Wheat Rust Pustule - Captured exploding from the leaf of a wheat plant, this pustule is the result of an infection by the fungus Puccinia graminis.