Polarised Light Microscopy of Chemicals, Pharmaceuticals and Health Care Products
There are many factors involved in making the pictures that are showcased here. These pictures were not designed and cannot be designed. Their formations are pure coincidences and are determined by a multitude of factors dictated by the rules of physics and chemistry. The colours that you are see are not artificially added but depend on the dance that occurs between the light and the nature of the crystalline structure of the sample.
Experimenting with chemical mixtures, tweaking of mixing ratios, adjustment of rates of cooling, using different solvents, tweaking of the light, looking for familiar patterns, composing and framing the picture are just some of the ways in which the hands on creativity of art and science are woven together. Each and every time you peer down the microscope you witness something new that for the most part, nobody has ever seen before. The entire process is meticulously recorded and observations documented in a recipe book. Through this series of imagery I hope to inspire an appreciation for nature and the sciences, and using imaging and microscopy to explore the interconnectedness of the chemical and natural world as well as the weaving of art and science. If you would like to purchase any then please send me an email through my contact page.
Colourful Tropical Plants
Not unlike some of the paintings by MC Escher the extravagant crystallographic patterns seen in this image of Vitamin-B3 take on the appearance of epiphytes. Epiphytes are arboreal plants that carpet and drape the branches and trunk of trees in the botanical heaven of the virgin rainforests in Southern America.
Living in the canopy, they extract water and nutrients wherever they can find them.
The Forest Floor
Light beams pass through openings in the dense canopy 120ft above, providing a patchwork of illumination on the forest floor. Flecked with leaves that appear to take on the form of double-stranded loops of deoxyribose nucleic acids (DNA). The characteristics of a living organism, called its phenotype, is determined by the presence of specific sequences of base pairs in its genetic material. The phenotype, of a plant for example, evolved over millions of years in adaptive responses to changing environments. Only those plants that adapted to the environment survived whilst others die out. This is called the theory of natural selection by Charles Darwin.
Amazonian Butterfly Wing Scales
Strikingly similar to the outline of butterfly wing scales, the 3D effect comes from a technique called oblique illumination and the colours from the dance between compensated polarised light and the molecular lattice of the crystalline film. Here we have a solute of Potassium ferricyanide doped with impurities of ferrous sulphate.
This supernova explosion imaged in x-ray reveals extremely hot and energetic plasma spiralling along the tightly wound magnetic field lines at the core and those emanating thousands of light years away from the source. Actually, this is I think a good example of self-similarity at different length scales. This is not an image from the cosmic scale but the essential amino acid, tryptophan.
The crystallisation of acicular or needle-like crystals occurs due to the higher rate of growth in one direction with respect to other directions. The growth rate depends on the density of molecules present in the solution, the more molecules present, the greater the number of molecules that can adhere to the liquid/crystal interface per unit time.
Lithium chloride exhibits anisotropic structural properties in its crystalline form, meaning that its crystal faces grow at different rates. The growth of lithium chloride crystals take on an acicular or needle-like morphology due to their higher growth rate in one direction with respect to other directions. Growth occurs because lithium chloride molecules dissolved in solution adsorb or attach onto the liquid/crystal interface.
Competeting Surface Tensions
Viscous liquid crystal with a drop of alcohol generates localised turbulent potential wells due to Marangoni effect.
With its large showy extravagant display of flowers and a member of the Mallow family Malvaceae, there exists several hundred species of Hibiscus plants throughout the world. This crystallographic formation is comprised predominantly of magnesium sulphate among others. Magnesium sulphate is used to treat and prevent low levels of magnesium in the blood, to treat convulsions during pregnancy, a specific type of abnormal heart rhythm called Torsades de pointes, asthma exacerbations and constipation. Imaged in compensated polarised light and captured at a magnification of around 120 times.
These two images bring to mind a particular plant native to Amazonia, the tropical climbing woody vine, Bougainvillea, also known as Veranera. Its beautiful magenta-scarlet inflorescence consists of three leaf-like petals called bracts that surround its delicate white flowers. Veranera conserves its resources by using the trees as scaffolds, wrapping their tendrils around the trunk and branches in a tight vice-like grip. By doing so, energy is conserved, allowing the plant to expend it on other processes like rapid growth and accelerated leaf production, which are alternately arranged along its stems. These images were made from a crystalline film of caesium chloride, an inorganic compound used in nuclear medicine in the treatment of cancer.
These two images imitate a colourful sunlit symbiotic reef teeming with life, reminding me of a quote from “The High Frontier” by Mark Moffett – “The canopy of the rainforest is to biologists, what the ocean is to marine explorers. The water of the rainforest reef is the balmy air itself through which minute organisms drift like plankton.” They were created from a mixture of various health supplements including amino acids.
Close-up image showing the fiery hot plasma in the turbulent stellar photosphere of a Star, our Sun. Not really, this is actually tryptophan. Tryptophan is an essential amino acid that has several important functions in the body including the balance of nitrogen in our cells and tissues, assists in the production of vitamin-b3 or niacin which in turn is an essential requirement for the synthesis of the neurotransmitter serotonin in the brain.
Autumn Come and Gone
It's Autumn in Northern Europe and the Sun’s radiance incident on the forest canopy is declining. The photosynthetic machinery within the trees foliage begins to break down and disintegrate, transforming into various shades of yellows, oranges and browns. Over time, they drop away from their parent trees and scatter the forest floor below. However, looks can be deceptive. These structures are not botanical in nature, but are crystallized organic compounds imaged under a microscope.
A specific ratio of two amino acids, when mixed and dissolved in a solvent and allowed to undergo evaporation, results in this stunning crystalline formation. The amino acids are beta-alanine and L-glutamine. The L- donates that the molecule has a left-handed structure, as opposed to a right-handed structure. When a plane-polarised light beam interacts with such a left-handed molecule, the electric field vector of the light wave is rotated through some angle (theta) in an anti-clockwise direction. In this case the molecule is said to be laevorotatory. All amino acids that link together through peptide bonding to form proteins are left-handed amino acids.
It’s night time in a shadow world of other wonders. The plants of the rain forest are lit by a full moon. Fireflies, attracted by aromatic molecules oozing out from specialised scent glands called osmophores on some types of flowers, swarm around them in a dance. The tropical forest is a labyrinth of fauna and flora species that all have a role to play in a highly interconnected and complex web of life. This image was created from a mixture of agricultural fertilizers and compounds used in the cosmetics industry. The imaged was captured in compensated polarised light at a magnification of 120 times.
Australian and Amazonian Wild Fires
This is one in a series of images I took which I think strikingly resembles a scene in which a cluster of exotic palms and ferns are engulfed in flames. This image captures the complex and organic like crystal structures that form from a combination of amino acids mixed in a specific ratio. The colours are derived from the interaction of compensated plane polarised light with the crystal.
Like a clump of ferns in a psychedlic forest, these crystal formations are the results of a specific mixing ratio of two chemicals which were melted and allowed to cool quickly. Subsequent attempts to try to reproduce similar structures from my recorded procedure have been to date unsuccessful making this set pretty unique in my portfolio.
Members of an indigenous tribe perform a ritual dance to music dating thousands of years, moving their bodies to praise their indigenous God. For the celebration they paint their faces using natural pigments, and wear colourful decorative clothing weaved from traditional fabrics, and jewellery and necklaces crafted out of plant seeds. Living in harmony with nature, they never take more than they need from nature, wasting nothing and replenishing its resources.
This is actually a crystallographic formation of vitamin-b3 imaged in crossed polarised light captured at a magnification of around 120 times.
Fractals in Amino Acids
L-arginine is one of the essential amino acids in biology which plays a role in balancing the electronic charge of a protein, ultimately to maintain its conformation. Here we can see frozen droplets of L-arginine. Transparent to the unaided eye, but when placed between crossed-polarisers, suddenly we can see the unseen, giving us a new perspective. Because the molten droplets were supercooled to a temperature below its freezing point, the convection currents had not time to dissipate and so appear frozen in space and time taking up a branching fractal-like pattern. In fact, it is not the convection currents which are frozen, but the material transported on these currents which have become solidified in space and time. The process of changing from a viscous state to the glass state is called vitrification.
Found in the cytoplasm of all cells, L-arginine is an essential amino acid which is involved in the synthesis of proteins through RNA translation. When the temperature of this substance is increased through the glass-transition temperature, it gradually changes state from a solid to a viscous state called a non-Newtonian fluid. Such a fluid exhibits both liquid and solid like properties and is said to be viscous. Here, some of these viscous droplets have pooled around air bubbles.
Niacinamide Flower (Vitamin-B3)
Circular shaped crystals called spherulites grow radially from a central nucleation point. The nucleation point could be a dust particle or undissolved crystal grains in the liquid phase. During the crystallisation process, molecules precipitate from the liquid solution and undergo adsorption onto the growing crystal faces. The Maltese cross-like pattern visible in each spherulite corresponds to those molecules which are orientated in such a way as to lie perpendicular to the optical axis of the analyser.
Commonly used in our daily lives, caffeine improves our mental awareness by stimulating our central nervous system. Caffeine crystals exhibit anisotropic structural properties in their crystalline form, giving rise to acicular or needle-shaped morphologies. Anisotropic in terms of the crystalline lattice means that the arrangement of atoms or molecules in one set of planes is different in another while in contrast, atomic planes are symmetrical in all directions in an isotropic lattice. This means that one face of the crystal is susceptible to adsorbing and making stronger molecular bonds with other molecules more so than its other crystalline faces.
The stage is set and the physical parameters are just right for the self-organisation of fluid instabilities which, if the conditions are right, occur between the transition from laminar flow to turbulent flow. Called dissipative structures in this dissipative system, they arise at the boundary of a shear flow, similar to how Kelvin-Helmholtz instabilities occur. This is the regime where the highly complex equations of non-linear mathematics dominate.
Experimenting with fluids. Some movies showing the beauty of science and fluid dynamics!
A close-up of Creatine magnified approximately 150 times. Initially, forming a heterogenous mixture, minute crystals of creatine were suspended in a solvent of water. The crystals, jittering about in the molecular storm of Brownian motion, undergo random walks, colliding and adhering to other crystals. Over time, these clusters increase in size, eventually forming the branched fractal structure seen here, called a Brownian Tree. This self-assembly process is called diffusion-limited-aggregation (DLA). The colours in the image are a result of thin film interference. Residual water fills the spaces between the branches. Surface tension causes the top surface of the water to form a meniscus along the branches. As such, close to the branches there is a sudden change in thickness of the fluid film which leads to a change in the wavelength (colour). Regions of the same colour correspond to equal film thickness.
Dopamine ‘Skittle Rain’
A small quantity of powder dopamine was placed on a glass slide and heated to a temperature exceeding its melting point. In doing so, it sizzled and splattered across the substrate, forming a random distribution of pools and microdroplets on the glass surface. In time, as the temperature decreased, these droplets slowly changed phase from liquid to the crystalline state were the molecules orientate themselves in such a way that the overall crystal exhibits an optical property called birefringence. Depending on both the thickness and orientation of the crystal grains, the frozen droplets appear to take on different interference colours.
In the upper part of the image, the yellow-white/pink banding is a result of variations in the density of the medium. These variations arose because of convection currents taking place in the viscous medium as the sample sat on a hot plate. The sample was cooled quickly and so the currents had not time to dissipate. Their presence manifest themselves as variations in the density and thus optical path length through the sample. Streamlines can be seen flowing around the bubbles as they experience a pressure difference which causes them to move in a direction away from the growing crystals.
Invisible made Visible
Fluid dynamics is the branch of physics describing the flow of liquids. The movement of liquid can be categorised as laminar or turbulent and the magnitude of that flow can be quantified by the Reynolds number. In this case, the fluid flowing around, and in the wake of the bubbles is smooth and laminar. This of course makes sense because the fluid here is a viscous ‘gloup’ of molten sucrose or table sugar and the bubbles move relatively slowly through it. Otherwise invisible, the flow is made visible here through a technique called differential interference contrast.
Brilliant Radiance in Vitamin-C (Ascorbic acid)
Four large crystals surrounded by an extremely thin film of Vitamin-C. The thin film, illuminated from beneath with plane-polarised light, results in strikingly colourful optical interference patterns. These patterns arise due to the complex interplay between the illuminating light field and the atomic planes of the doubly refracting crystal lattice. Bands of the same colour correspond to equal or integer multiples (1, 2, 3, …, n) of the wavelength differences in pathlength through the crystal. Dislocations in the crystal film can be seen as straight lines where the coloured bands appear to converge.
Radiant Vitamin-C (Ascorbic acid)
Two large bulk crystals surrounded by an extremely thin film of Vitamin-C. The thin film, illuminated from beneath with plane-polarised light, results in strikingly colourful interference patterns. These dazzling patterns arise due to the complex interplay between light and the doubly refracting or birefringent crystal film. Bands of the same colour correspond to equal or integer multiples (1, 2, 3, …, n) of the wavelength differences in pathlength through the crystal. Dislocations in the crystal film can be seen as straight lines where the coloured bands appear to converge.
Like oil splotches on a wet road, the coloured interference patterns occur when the thickness of the film is just right to support interference between the front and back surfaces of the film. Here, the patterns form around seed crystals. It is around these crystals that the film is thickest.
Voronoi Lattice - Dopamine Kaleidoscope
Powdered dopamine was smeared across a glass slide, melted and cooled to give rise to the formation of a vast number of individual crystal grains as it undergoes a change of phase from a liquid to a solid crystalline state. Because of the physical structure of this substance, dazzling kaleidoscopic colours can be seen when viewed through crossed polarisers. Such materials are said to be optically active as they twist the plane of polarisation of light.
This image brings to mind the famous painting, 'The Scream' by Edvard Munch.
This trippy psychedelic image was produced by mixing the essential amino acids, beta-alanine and L-glutamine in a specific ratio and dissolving the mixture in a solvent. The solvent was evaporated allowing the molecules to come out of solution and to adsorb onto the faces of the radially growing crystal from its nucleation point. Through experimentation of controlled cooling rates and other environmental factors, different types of crystal structures can be fashioned. However, it is never possible to reproduce such a complex crystal structure exactly since all crystals have defects inherent in their lattice structure. In essence it is never possible to reproduce any of these images.
Air Cavities in a Viscous Sugary Solution
In a race to minimise energy and reach an energetically favoured state of equilibrium, a tug-of-war ensues between many thousands of trapped air pockets and the compressing effects of the surrounding viscous liquid. A bubble is a balancing act of forces that occur between it's internal air pressure pushing outward on its membrane and the compressive forces of the surrounding liquid trying to crush it inwards. As a result, the molecular field density and thus the optical path length surrounding the air pockets will be significantly distorted. This effect can be seen by the vivid coloured bands immediately surrounding the bubble aggregations.