Polarized Light Digital Image Gallery
Featuring a wide spectrum of birefringent crystals and other anisotropic specimens, the MIC-D polarized image gallery contains digital images that were captured using the microscope at a variety of zoom optical system magnifications using crossed polarized illumination. In some cases, the specimen colors were further enhanced by addition of a first order retardation plate between the stage and analyzer. The images were corrected and adjusted with respect to contrast, brightness, sharpness, hue, color balance, and saturation using digital image processing tools available in the MIC-D software processing window.
Acetylcholine - Acetylcholine is both a central and peripheral neurotransmitter. Synthesized from dietary choline and acetyl coenzyme A, this neurotransmitter and similar substances play a central role in depression, therapies for Parkinson's and Alzheimer's diseases, and in chemical warfare against insects and humans.
Adenosine Triphosphate (ATP) - If the mitochondria are the "factories" of the cellular world, then adenosine triphosphate (ATP) is the chemical fuel that drives them. Adenosine triphosphate, the chemical energy currency of the plant and animal world, is required to for all the processes that keep organisms alive.
Ascorbic Acid (Vitamin C) - Known in the over-the-counter food supplement trade as vitamin C, ascorbic acid, a water-soluble organic compound, is the most studied and debated of all the vitamins. Commonly found in nature in peppers, citrus fruits, tomatoes, melons, broccoli, and green leafy vegetables, vitamin C assists the body in the production of collagen, but is widely believed to be a strong antioxidant, a fighter of cancer, and a key player in detoxifying the body of foreign substances.
Aspirin (Acetylsalicylic Acid) - Known to the pharmacist as acetylsalicylic acid, aspirin is an over-the-counter anti-inflammatory and antipyretic drug that also possesses highly effective non-opiate analgesic properties. Derived originally in nature from the bark of willows, the Greek physician Hippocrates (as in the Hippocratic Oath) used a powder extract to treat pain and reduce fever in the Fifth Century BC.
Beta-Carotene - When the wise-cracking cartoon character Bugs Bunny asks "what's up doc?" while chomping down another carrot, if one was an optometrist, one might answer, "good vision Bugs". The pigment, beta-carotene, that colors carrots, sweet potatoes, pumpkins, and other yellow and orange vegetables, is a precursor for vitamin A (retinol), an essential component for vision.
Biotin (Vitamin H) - As a water-soluble member of the B-complex family of vitamins, biotin is required for growth and metabolism in humans. Often referred to as vitamin H, biotin is found naturally in liver, kidney, soy flour, egg yolk, cereal grains, and yeast.
Brilliant Blue (Coomassie Blue) - Known also as coomassie blue, brilliant blue is a synthetic heterocyclic organic stain, which binds nonspecifically to virtually all proteins. Although not as sensitive as silver staining, brilliant blue and its derivatives are widely utilized because of convenience.
Calcium Chloride - A colorless or white solid, calcium chloride is well known for its anhydrous properties, with the capacity of absorbing more than its own weight of water. The inorganic crystalline compound is commonly employed as a drying agent and is often featured in small packets as packing for moisture-sensitive electronics and other products.
Cholesterol - Despite what some people believe, not all cholesterol is bad and you are not always what you eat, particularly if you are a vegetarian. In fact, cholesterol is essential to life, being a primary component of the membrane that surrounds every cell. It is also the precursor biochemical from which the body synthesizes bile acids, steroid hormones, and vitamin D. Cholesterol circulates in the bloodstream and is manufactured by the liver and several other organs.
Cinnamic Acid - Cinnamic acid, a derivative of phenylalanine, composes a relatively large family of organic acid isomers that are extracted from plants or synthesized in the laboratory or chemical factory. Most famous as the phenolic compound that gives oil of cinnamon its characteristic odor and flavor, cinnamic acid appears to have antibacterial, antifungal, and parasite fighting abilities. In wine, cinnamic acid and its derivatives join benzoic acid derivatives and flavinoids in creating pigments and tannin agents that give each vintage it characteristic bouquet and color.
Clozaril - Clozaril or clozapine, one of first new drugs designed for treating schizophrenia in over 20 years, was introduced in 1975 (1989 in United States) by Novartis Pharmaceuticals Corporation and is mostly used in Europe. Symptoms such as hallucinations, delusions, blunted affect, and hostility are successfully addressed with this synthesized antipsychotic pharmaceutical, which is also marketed as leponex.
Cresyl Violet - Cresyl violet is a synthetic dye that is widely utilized to stain neuronal tissues. Because it is a basic stain, it readily binds to the acidic components of the neuronal cytoplasm such as RNA-rich ribosomes, as well as the nuclei and nucleoli of the nerve cells. Cresyl violet should not be confused with crystal violet, a stain for distinguishing Gram positive and Gram negative bacteria.
Cytidine - As one of the four building blocks (nucleosides) of nucleic acids, life as we know it would not exist without cytidine (abbreviated C by biochemists and molecular biologists). A pyrimidine nucleoside similar to thymidine (T) in DNA or uridine (U) in RNA, cytidine is an aromatic single-ring nitrogen heterocycle (cytosine) bonded to a ribose sugar unit. In nucleic acids, pyrimidine nucleosides are hydrogen bonded to purines (guanidine (G) and adenosine (A)).
Diamond Thin Films - Chemical engineers create diamond thin films by sowing carbon atoms on a surface of silicon carbide. The miniature diamonds grow into interlocking molecular tetrahedrons, basically pyramids with triangles at their base.
2',3'-Dideoxycytidine (ddC) - 2',3'-dideoxycytidine (ddC) is a prescribed pharmaceutical used in the treatment of AIDS, often in combination with AZT (3'-azidothymidine) or other drugs. Although this drug therapy does not cure the deadly malady, dideoxycytidine and its relatives help slow down the destruction of the patient's immune system by the HIV virus.
Diethylstilbesterol (DES) - Diethylstilbesterol (or diethylstilbetrol; DES) was a drug prescribed to women from 1938 through 1971 to prevent miscarriages in high-risk pregnancies. However, acting as a potent estrogen, exposed female fetuses had an increased risk to developing abnormal reproductive tracts and cancer.
Docosahexaenoic Acid (DHA) - Docosahexaenoic (or docosahexanoic) acid (DHA), one of the omega-3 fatty acids, appears to possess beneficial influences on human visual function and may be important in the infant diet. The triple long-chain polyunsaturated fatty acid DHA is one of the least saturated fatty acids in the human body, and is highly enriched in the membrane lipids of rod photoreceptors in the human eye, but also concentrates in the brain. Docosahexaenoic acid, sometimes referred to by nutritionists as "brain oil," is one of the primary structural components of brain tissues, which are 60 percent fats.
Dopamine (Dopastat) - Dopamine is a naturally occurring immediate precursor of norepinephrine, and also a synthesized organic compound that is used to correct hemodynamic imbalances due to shock, trauma, and renal failure. The drug causes an increase in cardiac output and vasoconstriction in blood vessels, and when low doses are administered, causes renal and mesenteric vasodilatation. Side effects include nausea, vomiting, headache, and anxiety.
Erythromycin - Erythromycin is a wide-spectrum antibiotic that is used in ophthalmic, topical, and systemic treatment of bacterial infections. It is particularly useful in patients with a history of allergies towards other antibiotics, such as penicillin.
Estradiol - As one of the endogenous estrogen female sex hormones, estradiol is used in hormone replacement therapy associated with menopause and helps prevent osteoporosis in older women. Estradiol is the principal estrogen found in a woman's body during her reproductive years and is produced by her ovaries. It is much more potent than estriol, and acts an inhibitor of ovulation by inhibiting the release of follicle-stimulating hormone (FSH).
Ethidium Bromide - Ethidium bromide, commonly employed in molecular biology laboratories, has been widely used for many years as a nucleic acid stain and a non-radioactive marker for identifying and visualizing nucleic acid bands in electrophoresis. A reddish-orange fluorescence can be detected under both long and short ultraviolet (UV) wavelengths of light, with increased fluorescence when bound to double-stranded DNA.
Folic Acid (Folate) - Folic acid is a water-soluble B vitamin found naturally in Brewer's yeast, liver, most types of berries, leafy vegetables, citrus fruits and juices, rice, soybeans, and wheat. Whether natural or synthesized, folate promotes the formation of red blood cells, helps maintain the central nervous system (CNS), and promotes normal development and growth.
Gamma-Endorphin - Pleasant memories, such as that first birthday party with your friends, or that trip to Yellowstone National Park, and even bad memories, are linked to the autonomic nervous system and the brain stem. Endorphins, a class of neurohormones, act by modifying the way in which nerve cells respond to transmitters and are associated with feelings of pain and pleasure.
Glucose - Glucose is one of the substances that corn and grapes have in common, and the fermentation of this natural sugar into whiskey or wine is what has made human civilization sometimes tolerable during tough times. Also known as dextrose, glucose is a six-carbon sugar or hexose and a monosaccharide.
Glutamic Acid - Glutamic acid, a negatively charged amino acid, is found often on the surface of proteins in plants and animals. As an important metabolic intermediate in animals, glutamic acid is a nonessential amino acid that can be biosynthesized during the metabolism of carbohydrates or obtained directly from dietary sources.
Ibuprofen - Ibuprofen is a nonsteroidal anti-inflammatory drug that is used to treat symptoms caused by arthritis, such as swelling, pain, and stiffness. This drug is widely available without prescription and is marketed under a variety of trade names including Advil, Nuprin, and the original McNeil-PPC formulation, Motrin.
Inositol - Naturally found in green leafy vegetables, inositol is a water-soluble sugar that performs well as a fat emulsifier, an anti-anxiety agent, a controller of serum cholesterol, and helps maintain healthy hair. Also known as meat sugar, inositol, a non-essential vitamin/sugar, is vital for cell membrane functioning and maintenance.
Lauric Acid - As one of the medium-length long-chain fatty acids, lauric acid is part of the class of organic compounds known as lipids, which are vital in the construction of cellular membranes and act as a source of food under starvation conditions. Contrary to popular beliefs, natural coconut and coconut milk are good for the health, mostly because of their high lauric acid content.
Lead Oxide - Lead oxide constitutes a family of compounds with varying numbers of oxygen atoms per molecule, depending on the valence state (+2 or +4) of the lead, and varying crystal morphs, even with the same chemical formulas. These compounds are familiar to geologists as ores and crystal minerals, to inorganic chemists, and to manufacturers as pigments.
Leptin - A protein hormone, leptin is manufactured in adipose tissue (fat cells) and acts on receptors in the hypothalamus of the brain. The level of circulating leptin is directly proportional to the total amount of fat in the body and leptin helps maintain the homeostatic control of food intake.
Magnesium Sulfate - Large crystals of magnesium sulfate are rare, while crusts and massive forms are much more common. Epsomite (the mineral form of magnesium sulfate) forms as a precipitation from vapors (efflorescent) on limestone cave walls and on the walls and timbers of deep-shaft mines. In addition to the solubility of the crystals, the bitter, salty taste of epsomite is very characteristic of the compound. The dust of the salt is irritating to the eyes and throat as may be experienced by exposure to dry lake beds.
Mannose - As a six-carbon simple sugar, mannose (or dextro-mannose) is a stereoisomer of glucose that is found as an uncommon, naturally occurring saccharide in some plants, particularly legumes, and other food plants. While small amounts of d-mannose are metabolized in the human body, large quantities of the hexose are excreted rapidly into the urine.
Menadione (Vitamin K) - A fat-soluble vitamin precursor, menadione is converted to menaquinone in the liver. The primary function of vitamin K in the body is to assist in normal blood clotting, but it also plays a role in bone calcification.
Methylene Blue - A chemically basic dye, methylene blue is also known as tetramethyl thionin, and there are various grades used, including methylene blue chloride, which is preferred for biological work. The dye is easily oxidized and often contains azure B and methylene violet, depending on the manufacturer.
Mifepristone (RU-486) - Dubbed the "French abortion pill" and the "month after pill", the pharmaceutical RU-486 hit the European scene like gangbusters in 1988, but was delayed for licensing in the United States by the Food and Drug Administration because of political pressure against abortions until September 2000. In France, where the drug was developed, about one third of all abortions are performed with the synthetic steroidal hormone.
Nicotinamide Adenine Dinucleotide (NAD) - Nicotinamide adenine dinucleotide (NAD) and the phosphate derivative, NADP, are two coenzymes that are regularly utilized in the body for electron-transfer biochemical reactions as carriers of hydrogen ions. NADH (the reduced form of NAD) is the active coenzyme form of vitamin B-3 and is necessary for the production of cellular energy and integral in the development of essential neurotransmitters.
Niacin (Vitamin B-3) - Niacin (vitamin B-3), more commonly known as nicotinamide in the biochemical community, plays an important role in the biosynthesis of pyridine nucleotides. This nitrogen heterocyclic organic compound is combined in vivo with the nucleotide adenosine to form nicotinamide adenine dinucleotide (NAD).
Nickel Sulfate - As a non-caking salt used for nickel plating, each molecule of the nickel sulfate crystal is usually hydrated with six molecules of water. Known also as nickelous sulfate and sulfuric acid nickel (2+) salt, the mineral is sometimes used in homeopathic remedies for treating seborrheic dermatitis and chronic dandruff.
Nicotine - As one of the few liquid alkaloids, nicotine constitutes about 5 percent of a tobacco plant by weight. While nicotine is found throughout the tobacco plant, it occurs in the highest concentrations in the leaves, and ranges from 1 to 8 percent by weight in a typical cigarette.
Norepinephrine - As a neurotransmitter in the catecholamine family, norepinephrine mediates chemical communications in the autonomic nervous system's sympathetic network. Norepinephrine is released at the synapses (in a manner similar to other neurotransmitters), transmitting neural signals from a nerve to other cells in the body.
Oleic Acid - Olive oil, the elixir at the foundation of Mediterranean civilizations, features from 55 to 85 percent oleic acid and about 9 percent linoleic acid as component fatty acids. The health and therapeutic benefits of olive oil have long been appreciated as evidenced by Hippocrates, the father of medicine, singing its praises. Unlike dietary fat perceived as bad for health, oleic acid is a monosaturated fat believed to help reduce serum cholesterol levels and low-density lipoproteins or LDLs ("bad" cholesterol), while not affecting levels of high-density lipoproteins or HDLs ("good" cholesterol).
Orotic Acid - Orotic acid plays a central role in the metabolism of folic acid and vitamin B-12, and may enhance the transportation of minerals across cell membranes. Found naturally in whey and root vegetables, such as beets, turnips, and carrots, orotic acid is easily destroyed by water and sunlight.
Para-aminobenzoic Acid (PABA) - Para-aminobenzoic acid (PABA), a component of pteroylglutamate, was once considered a vitamin and named vitamin B-X because it serves as a provitamin for some bacteria. Later studies in humans demonstrated that the chemical does not have vitamin activity because humans lack the ability to synthesize folate from PABA.
Pantothenic Acid - Pantothenic acid, a B-complex vitamin, is essential for growth, reproduction and normal metabolic processes in humans and other animals. Common dietary sources of pantothenic acid are yogurt, lentils, eggs, liver, meats, lobster, avocado, mushrooms, sweet potato, soybeans, brewer's yeast, and wheat germ.
Phenylacetic Acid - An aromatic ring compound, phenylacetic acid appears to influence mood and fight depression. Phenylketonuria, a inherited error of catabolism that can cause mental retardation, results in elevated serum levels of the amino acid phenylalanine, some of which is eliminated in the urine and sweat as phenylacetic acid, creating a diagnostic "mousy" body odor.
Picric Acid - The first synthetic dye, picric acid, was prepared in 1771 by British chemist Peter Woulfe from the extraction of the natural plant pigment, indigo, treated with nitric acid. Initially used for silk in 1849, picric acid was employed as a yellow dye until 1885 when French organic chemist Jean-Baptiste-André Dumas realized that the yellow crystal was highly explosive.
Potassium Chloride (KCl) - Potassium chloride, known to some as "diet salt", reflects similar chemical and crystalline properties to common salt or sodium chloride. Lower grade potassium chloride is used as an ice melting agent that is relatively harmless to vegetation, aquatic ecosystems, and concrete when contrasted to rock salt or sodium chloride.
Progesterone - Progesterone is a steroidal hormone that plays a central role in the female reproductive cycle. The sex hormone is produced primarily by the adrenal glands, the placenta, and the corpus luteum of the ovaries. In the absence of oocyte fertilization during ovulation, natural progesterone levels in the blood serum decline, and menstruation begins. However, if the egg is fertilized, progesterone levels will increase to support the pregnancy, maintain the corpus luteum, and promote mammary gland development and milk production.
Prostaglandin A1 - Prostaglandins are members of the lipid class of biochemicals and are known for their potent physiological properties by regulating fat metabolism, inflammatory response, hormones, as well as the cardiovascular, immune, and central nervous systems. They belong to a subclass of lipids known as the eicosanoids, because of their structural similarities to the C-20 polyunsaturated fatty acids (the eicosaenoic acids).
Retinoic Acid (Vitamin A) - As a naturally occurring form of vitamin A, retinoic acid (or tretinoin) may be used topically for sun-damaged and acne-plagued skin. While the related and less effective retinol is allowed in cosmetic products, the United States Food and Drug Administration regulates retinoic acid as a prescription pharmaceutical as featured in the trade formulations Renova and Retin-A.
Riboflavin (Vitamin B-2) - Riboflavin, also known as vitamin B-2, is a water-soluble vitamin that promotes normal growth, facilitates the breakdown of fat, and aids the syntheses of steroids, red blood cells, and glycogen. Natural sources of vitamin B-2 include almonds, yeast, cheese, eggs, chicken, beef, organ meats, and wheat germ.
Serotonin - A monoamine neurotransmitter, serotonin involves many sensory and higher centers in the brain including memory, appetite, sleep, and learning. Known to many as the "feel good" hormone, serotonin, along with endorphins, GABA, and dopamine, form the biological process known as the reward cascade.
Silver Bromide - Historically used in photography, silver bromide crystals are finding new life in very deep infrared applications as windows and lenses, particularly when sensitivity to moisture is an issue. Under heat and pressure, the soft silver bromide crystal deforms and can be forged against polished dies to create optical elements.
Sulforaphane - When your grandmother told you to eat all your broccoli from the dinner plate, she did not anticipate the findings of biochemists and oncologists that the controversial green vegetable is loaded with sulforaphane, a naturally occurring sulfur-containing isothiocyanate derivative. This phytochemical swings into action within hours of ingestion and triggers an immune response to carcinogenic substances.
Tacrine (Cognex) - Although tacrine was marketed for many years as a respiratory stimulant, only recently has it been prescribed to treat the symptoms of mild to moderate Alzheimer's disease. Marketed under the trade name Cognex, the reversible cholinesterase inhibitor does not cure or slow the progression of the debilitating disease, but rather allows the patient to improve thinking ability.
Taxol (Paclitaxel) - Taxol is a member of the anti-neoplastic (anti-cancer) class of chemicals that is used to combat the proliferation of cancer. The primary focus of Taxol is treatment of ovarian and breast cancer by stopping mitosis when other avenues of chemotherapy have failed. Originally extracted from the bark of the endangered Pacific yew (Taxus brevifolia, this wonder drug led to quite a controversy in the environmental community, because it meant the death of four trees to produce enough taxol for a single human dose.
Testosterone - Testosterone is the major steroidal hormone produced by the interstitial cells of Leydig in the male testes. Lesser amounts of this hormone are produced in the adrenal glands of both sexes. Synthetic testosterone forms a white or slightly creamy white crystalline powder or crystals that are practically insoluble in water and freely soluble in alcohol, chloroform, and vegetable oils. Odorless, crystalline testosterone melts from 153 to 157 degrees Celsius.
Thiamine (Vitamin B-1) - Thiamine (more commonly referred to as vitamin B-1) was previously known as the anti-beriberi factor, and is essential for carbohydrate metabolism as a coenzyme. Aerobic metabolism and the conduction of nerve impulses also involves vitamin B-1. Thiamine is unstable to heat, alkali, oxygen, and radiation. As a B-complex vitamin, thiamine is soluble in water and in the body, supplies are rapidly depleted, and must be replaced regularly. An overdose of vitamin B-1 (thiamine shock) is indicated by weakness, a burning sensation, nausea, gastrointestinal hemorrhage, pulmonary edema, collapse, and even death.
Uridine - As one of the four nucleosides used in genetic coding for RNA, uridine contains a pyrimidine base (uracil), which is structurally related to thymidine (linked to a ribose sugar) found in DNA strands. In RNA, the complement to uridine is the nucleoside adenosine and when a phosphate is attached, the nucleotide uridine monophosphate (UMP) is formed.
Pyridoxine (Vitamin B-6) - As one of the central vitamins in the B-complex, pyridoxine (better known as vitamin B-6) is a water-soluble nutrient that is vital as a precursor to a coenzyme involved in transaminations, decarboxylations, racemizations, and numerous modifications to amino acid side chains. In humans, pyridoxine promotes the normal functioning of the brain, blood formation, body fluid balance, and assists in the metabolism of carbohydrates, proteins, and fats.
Vitamin E (alpha-Tocopheryl) - Known to millions as vitamin E, d-alpha-tocopheryl acetate is a fat-soluble vitamin, which is stored in the liver, muscle, adipose tissue, red blood cells, and several vital organs and glands. Vitamin E, a strong antioxidant, plays a starring role in protecting body tissues from damaging free radicals as well as critical functions in cellular respiration and for prolonging the life of red blood cells.
Omar Alvarado, Thomas J. Fellers and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.
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