cannabis microscope

Over the course of the past year I have been working on creating images for a recently released book. Cannabis Under The Microscope: A Visual Exploration of Medicinal Sativa and C. Indica by Ford McCann. The book is a digital release on Kindle. The images cover numerous techniques from macro photography to scanning electron microscopy. I hope these images will be of interest to Micscape readers.

A cannabis seed at three days old. The seeds were incubated at (21ºC) on a damp paper towel and kept in the dark. The image was taken at 3x with a Canon macro lens and was focus stacked from 20 individual images. The images were collected with a stack-shot manufactured by Cognisys and combined using Zerene stacker software. Many of the following optical images used similar techniques.

Young sprout at 5 days, Note the concentration of trichome structures to deter bugs from eating the new leaves. The fresh leaves are the target for insects, so the plant increases the concentration of toxins at these locations to detour attack. The trichomes (spherical or needle like structures) are the location on the plant with the highest concentration of THC. THC is the active chemical that is responsible for the principal psychoactive properties of the cannabis plant. The plant uses this toxin to repel insect attack. This image is focus stacked from 20 images and was collected at 5x with a Canon 68mm macro lens. Images were focus stacked with Zerene software.

The surface of a cannabis seed seen under a scanning electron microscope. Magnification of the image shows a section of the seed coat approximately 0.2 mm across. The surface of the seed is a grooved structure that serves two different purposes: to absorb water and the strange shape is postulated to make the growth of bacteria difficult. Image taken with a Cambridge S200 scanning electron microscope. [Editor’s note: Ted runs the SEM from his house, see this Micscape article.]

A scanning electron microscope image SEM image of a nice elongated trichome structure on the top of a cannabis leaf. These cell structures act as thorns on the leaf top. The image was false colorized in Photoshop and represents a section of the leaf 0.2 mm wide.

An SEM image of the cross section of the major leaf vein. The bottom of the image is the bottom of the leaf. The structure is for support as well as holding the pith cells that help transport nutrients throughout the leaf. The image represents a section of the leaf approximately 3 mm across.

An optical image of the cross section of a leaf support (petiole). The notch in the structure points up and is believed to be associated with water flow over the leaf structure. The center of the structure is where the pith cells are located, in a mature leaf the center section would be completely filled with pith cells. This section has been dyed with neutral red and brilliant crystal blue. This picture of the petiole shows a 3 mm wide field of view. The image is a panoramic made from 18 individual images and combined with the panoramic feature in Photoshop.

A sample of the bottom of a cannabis leaf about 3 mm wide. Two types of defensive cell structures are clearly visible: the tall needlelike trichomes and the short ball like glandular trichomes that are the source of the highest levels of THC. The high density of trichomes on modern cannabis leaves should make them a good source of THC. This is a false color SEM image with false color looking from the central rib on the bottom of a leaf towards the edge of the blade.

This is a highly magnification SEM image of the cell structure that allows the carbon dioxide to enter inside the leaf. This is the leaf stoma. The structure is made of two cells called the guard cells that open and close the vent depending on the time of day.

All three shots are SEM images of the bottom of the leaf. Just look at all those trichomes! Tall needlelike defensive trichomes, and the short spherical glandular trichomes which produce high levels of THC. The chemical THC is produced by the plant to ward off insect and herbivore predators . It just so happens that humans find this chemical of medical interest, and have crossbred the plant to increase the THC levels. THC is shorthand for Tetrahydrocannabinol also known as (( 6aR,10aR)-delta-9-tetrahydrocannabinol), it is the psychoactive chemical in the cannabis plant. THC was first isolated in 1964 by Israeli scientists Raphael Mechoulam and Yechiel Gaoni . If you look closely at the surface you can see the stoma structures scattered around the leaf surface that allow the leaf to breathe .

Scanning electron microscope images of the bud of a cannabis plant. This image shows the diverse forms the trichomes exhibit at the plant bud. The bud of the female plant is also the location of the highest concentration of the medicine THC. Recent measurements have shown that the concentration of THC has been found to be above 8% of the weight of the bud. These measurements are highly variable, depending on water content of the bud and techniques used to measure. The concentration of THC continues to increase due to active breading research.

An individual glandular trichome. Approximately 0.05 mm high, the glandular trichome is the source of the highest concentration of THC in cannabis most often found on the bottom of the leaf and in the plant bud.

A 4 mm wide SEM view of the female flower pistil. These are very difficult structures to prepare for viewing in the SEM vacuum. The sign of a well prepared sample is that the majority of the glandular structures are full and not deflated. Samples like this were prepared with a 2.5% solution of glutaraldehyde within minutes of being collected from a living plant in California. The specimen then when through a series of increasing concentration of ethanol before removal of any liquids with a critical point dryer. All of the SEM samples were taken through a similar process and gold plated in a sputter coater before imaging. The gold coating insures that the sample is electrically conductive, a requirement for achieving good images in a scanning electron microscope.

A cross section of a mature stem. The image is 6 mm wide. The different layers of the stem have been given different colors. The layer that is several cells below the skin is the section of thick-walled fiber cells. This highlights one potential uses of cannabis: an excellent source of fibers for paper, rope, and fabric. The legalizing of cannabis in several states in the United States, opens research in this very profitable aspect of the plant.

An optical microscope shows the pith cells and the cell wall structures. Dyed with brilliant crystal blue stain to show the cell walls. The pith cells are located in the center of the stem and are responsible for storing and transporting nutrients throughout the plant.

A false color SEM image of a calcium oxalate crystal. Even a small dose of calcium oxalate is enough to cause intense sensations of burning in the mouth and throat. Commonly found in popular houseplants, such as Dumbcane , the crystals effects or symptoms may last for a week or more, making raphides a non-desirable ingredient in medicinal cannabis. It is surprising that calcium oxalate is rarely discussed in literature about medical marijuana (cannabis).

If you would like to see the rest of the images, the full book is available at here.

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Published in the May 2014 edition of Micscape.
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Over the course of the past year I have been working on creating images for a recently released book. Cannabis Under The Microscope: A Visual Exploration of Medicinal Sativa and C. Indica by Ford

Microscopes Give You A Closer Look At Cannabis Plants

Many kinds of microscopes and magnifying lenses are available to help you get a closer look at your cannabis plants. From pest prevention to harvest timing, these devices will help you throughout the entire grow cycle, and might even save your crop from infestation or attack.

Every grower should obtain a magnifying lens or microscope for their toolbox. These simple and useful devices can really help in every stage of a plant’s life, and even after. Lenses and microscopes might also assist those who aren’t growers, but would like to check the quality of a sample before buying the whole batch.

Deciding when to initiate harvest is one of the cannabis grower’s most pivotal decisions. Regardless of whether you are a seasoned hand or a newbie, a microscope will allow any grower to ascertain the ideal harvest window to achieve maximum yield and peak cannabinoid concentration. How is this done? By observing the minute trichomes on your cannabis plant’s flowers. By evaluating the trichome structure, transparency, and hue, you will know exactly when to make the chop.

A microscope, or at least a good magnifying lens, is also useful to inspect freshly harvested, dried, or cured cannabis flowers for mould or parasite residues. An electron microscope could even spot crystals of chemicals such as pesticides, but that’s not a tool for the average grower or consumer. Let’s stay optical and learn how to evaluate trichomes and recognise pests.


Every grower knows: the more trichomes, the better. That’s because these tiny “hairs” don’t just contain the terpenes that defend the plant from animals, pathogens, or harsh environmental conditions, but also the cannabinoids that humans have come to know and love. The largest trichomes will be visible to the naked eye, while most will appear as a white or grey fuzz on the flowers of ripening cannabis plants. All of them are involved in the synthesis of cannabinoids and terpenes.

The cannabis plant features bulbous trichomes, which look like small pointed structures; capitate sessile trichomes, bigger and flattened; and capitate-stalked trichomes, the largest type of trichomes, which develop during the flowering stage. A microscope allows a clear look at the colours and transparency of the glandular trichomes’ resinous heads, mainly depending on the maturity of the plant. In most cases, the flowers are harvested when the heads start turning amber and opaque.


The clever grower knows it’s better to take a closer look at the plants well before trichomes start to develop. That’s because eliminating an infestation, whether it’s mould, spider mites, or any other kind of micro-invader, is much easier when the population has not had enough time to breed and expand its infestation on your plants. Pests often go unnoticed until too late because at early stages of an infestation, there are few visible signs on the plant. However, with a proper magnifying device, it’s possible, for example, to flush out spider mite egg clusters before they turn into adults and start chewing your leaves. In other words, a magnifying tool can save your crop.


The process of using a microscope or magnifying lens to judge your plants is a mostly straightforward venture; point the device at a leaf or bud and focus to view trichomes, or to spot any form of life that’s not your plant. The higher the magnification of the lens, the closer it must be to the specimen. A built-in light is useful to better illuminate the area even during daytime, and also for viewing plants during the dark hours in an indoor grow without having the lights alter the perception of trichome colour (a quick flash won’t change your plants’ sex, don’t worry).

With a magnifying device, resolution is just as important as magnification. If your trichomes cannot be clearly viewed because your lens mixes up all the small details, the image quality will be poor regardless of the magnification. The resolution is determined by the light frequency and the lens quality. The shorter the wavelength illuminating the specimen, the greater the resolution. Light also affects contrast; the more intense the light, the more contrast you get, up to the point where everything gets “solarised”.

Learning how to use a magnifying device doesn’t take much time, while picking the right one can be tricky, since the market is flooded with poor-quality lenses of every kind. Here is an overview of the different types of magnifiers to help you narrow down the search for your ideal tool.


The simplest microscope is a single lens, preferably with a decent magnification factor. Single lenses have a low magnification factor and a high optical aberration, which can produce distorted and blurred views, particularly around its borders. On a positive note, handheld magnifiers have a convenient wide viewing angle, and they are useful for a quick fly over your plants in search of “big” parasites, their residues, or small mould patches. A magnifying glass can’t help in viewing microscopic bugs, but it allows for a general view of the colour and transparency of trichomes—which is much better than relying on the flowering time indicated on your package of seeds.

Old-school jeweler’s loupes are the smallest pocket microscopes. Their lens (or lenses) is contained in a cylinder or cone, or it folds into a protective housing. Jeweler’s loupes are used in a number of industries, with some differentiation: simple lenses, compound lenses, or prismatic multiple lenses with higher magnification and less optical aberration. These tiny devices are very convenient for the grower, and some models come with an integrated LED light that’s especially useful in indoor operations. Jeweler’s loupes can also be placed on the camera lens of a smartphone to take pictures.


These are convenient hands-free magnification devices that add precision and speed to several tasks in different industries. They provide binocular 3D vision with a magnification usually limited to 3.5X. They might increase work efficiency on certain jobs in the grow room, but they can’t be the only magnification device at hand.


Pocket microscopes are relatively cheap and very popular among trichome-inspectors. They are able to produce beautiful images and they provide magnification up to 100X. Most of them have a built-in LED light for clearer viewing, and some models can be used with a smartphone. The problem with these high-magnification devices is that both the microscope and the sample must be perfectly still. This gets frustrating when trying to inspect a flower or a leaf on a branch. Many pocket microscopes come with a base and a movable arm that is supposed to hold the device, but rarely does in cheaper models.

USB pocket microscopes are cheap and convenient, but they must be connected to a laptop or desktop computer. High-quality, portable, digital, stereo, cordless, and wireless microscopes connected to a computer and a big screen are also available for the professional, or for the trichome-porn fanatic. On the other hand, many people already have a smartphone and use it as a portable magnifying tool. Some newer phones can produce high-quality pictures by themselves, while others need additional lenses to get a better view.


The classic, modern microscope has a series of lenses with magnification usually ranging from 10X to 100X. This device is ideal for viewing details of trichomes and other parts of the plant, together with occasional microscopic parasites. Of course, the specimen must be detached from the branch and prepared for viewing under the objective. The stereo tabletop microscope is not something for every grower, but it’s a must for both professionals and biology enthusiasts who want to ensure their grow is clear from pests, and that trichomes are just right before harvest. When researching cannabis, a decent microscope is also useful to analyse plant structures and trichome density on different parts of the anatomy. A “fluorescence microscope” is a version of the optical microscope that allows for enhanced details and contrast.


Optical microscopes are limited in resolution by the frequency of the light waves. Electron microscopes use electromagnetic beams with a shorter wavelength than visible light, which allows a higher resolution and magnifying factor. Needless to say, these kinds of microscopes are pretty complex and expensive, and are probably not something the average grower wants to deal with or invest in. Nevertheless, they are a great instrument to study nature and the secrets hidden in your weed.

Whatever device you wish to use, any cannabis grow will be enhanced with the use of magnifying tools. An entire world awaits under the lens of your microscope.

A microscope or magnifying lens can expand your knowledge of cannabis anatomy, protect it from pests, and help you decide the right time to harvest. ]]>