Cryo-Electron Microscopy

In the midst of this pandemic, almost everyone is acquainted with the token Covid-19 protein image. This image has surfaced on all facets of the internet, used as the primary visual in multitudes of articles and media blasts. However, given the extremely small size of the protein, how were scientists able to construct this 3D representation?

Scientists utilized Cryo-Electron Microscopy (Cryo-EM), an imaging technique which involves shooting electron beams at biomolecules to create microscopic snapshots of the individual molecules, which are later used to produce the 3D image of the structure. The breakthrough of utilizing electron beams rather than light beams was due to resolution and wavelength. Theoretically, a much higher resolution image can be produced using electron beams as the electrons wavelength is much shorter (than light) and can uncover sharper and more detailed images than other imaging techniques (Ex: super-resolution light microscopy). Standard Transmission electron microscopes (TEMs) project a beam of electrons through a narrow sample, which interacts with the molecules. The microscope then projects a picture of the sample onto a detector. However, there are many challenges in the TEM technique. Many biomolecules are not well suited for strong beams of electrons and high-vacuum practices involved in standard TEM’s. This process is not suitable for structures made up of organic molecules and biomolecules, as propelling electron beams at living matter can be calamitous. These electron beams cause radiation damage, which destroy the structure. (the beams penetrate the specimen, breaking bonds, and altering structure into burned products-the water abutting the sample molecules evaporates, thus burning and tarnishing the molecules). This explains why in early attempts of electron microscopy, the samples were demolished. 

Given the drawbacks of traditional TEM, what other imaging methods were used to capture and study biomolecules in the past?

For decades, researchers have utilized X Ray Crystallography and Nuclear Magnetic Resonance Spectroscopy for imaging. X-ray crystallography involves crystallizing biomolecules and striking them repeatedly with X-rays. Later using the resulting patterns of light [diffracted] to recreate the structure.

X Ray Crystallography

This method is able to create superlative structures, but also has certain disadvantages.  For the process to work, the biomolecule sample must crystallize, which is not feasible for many biomolecules Many of the body’s biomolecules floppy nature makes them arduous (or even impossible) to crystallize. Even the few that can often require months and years to crystallize. NMR also works best for smaller biomolecules with low molecular weights, and therefore cannot be used to observe much larger proteins or viruses. 

Cryo-EM avoids these issues without reducing the quality of the image.

Cryo-EM researchers began working on crystals of the protein bacteriorhodopsin at room temperature. However, by cooling the biomolecules to liquid nitrogen, they were able to derive 4-5x as much data from the images before any substantial radiation damage. While cooling a specimen does not halt radiation damage, but it reduces the consequences of radiation damage 4-5x. 

What is the process of Cryo-Em Specifically?

A protein is plunged in a very thin film of liquid (an aqueous solution) and then frozen in liquid ethane (The samples are lowered to cryogenic temperatures). An electron gun then bombards the sample with electrons, at the speed of light, which penetrate through it. An advanced camera then captures 2D images of the sample from different orientations. Finally, the system reconstitutes the different angled images and develops a detailed 3D structure. 


The true power of Cryo-EM is the ability to freeze and image a myriad of organic structures: pieces of tissue, solutions of molecules, ribosomes, suspensions of viruses. An example is the freezing of a suspension of ribosomes from a variety of cells. A thin layer of 15-20,000 ribosomes is frozen. As electron beams pass through, images from different angles are taken and then reconstituted to form an average 3d model.

What is the impact?

These images are useful for observing protein function, and malfunction when riddled with disease. Knowing where all the crevices and pockets there are in a protein are vital as they help chemists design drugs which fit into them. 

Through this process, scientists using Cryo-EM were able to image and create the famed Covid-19 protein image we see today. By identifying the crevices and the shape of the virus, chemists continue sampling potential drugs to achieve the right fit. This image was the turning point of research, and successfully directed scientists a path to finding the cure.

Works Referenced

“A 3 Minute Introduction to CryoEM.” Youtube, 17 Aug. 2011,

Anderson, Mark. “The History of Cryo-EM.” The History of Cryo-Electron Microscopy | Thermo Fisher Scientific, 15 Oct. 2019,

Broadwith2017-10-04T15:17:00+01:00, Phillip. “Explainer: What Is Cryo-Electron Microscopy.” Chemistry World, 4 Oct. 2017,

Callaway, Ewen. “Revolutionary Cryo-EM Is Taking over Structural Biology.” Nature News, Nature Publishing Group, 10 Feb. 2020,

Milne, Jacqueline L S, et al. “Cryo-Electron Microscopy–a Primer for the Non-Microscopist.” The FEBS Journal, U.S. National Library of Medicine, Jan. 2013,

Renaud, Jean-Paul, et al. “Cryo-EM in Drug Discovery: Achievements, Limitations and Prospects.” Nature News, Nature Publishing Group, 8 June 2018,

How do hospitals deal with MRSA?

Superbugs! They’re the hospital’s worst nightmare. They have the power to cause pneumonia, skin infections, urinary tract infections, and can even result in death. Most prevalent in hospitals, it’s not astonishing that healthcare workers must take serious precaution to prevent any spreads.

First, what are superbugs? Superbugs are bacteria, which are not easily killed by existing drugs due to antibiotic resistance. A notorious superbug is MRSA (Methicillin-resistant Staphylococcus aureus) also known as the infamous “flesh eating bacteria” which essentially causes infections in the skin. MRSA is resistant to amoxicillin, oxacillin, methicillin,  and penicillin.

MRSA Cells – Helix Magazine

The infection starts with painful, swollen, and red bumps which appear on the skin surface. These bumps feel warm to the touch and contain pus (a thick yellowish opaque liquid which consists of dead white blood cells and bacteria, commonly produced in infected tissue). These bumps rapidly transcend into painful abscesses which require surgical draining. MRSA generally infects skin around open wounds, but may also infect undamaged, intact skin.

Occasionally, the bacteria remains confined to the skin surface, however has the ability to enter the body. The bacteria enters through and can potentially cause severe infections and trauma in the bloodstream, heart valves, joints, and lungs.

MRSA is contagious as well and is spread by skin contact. Thus, those who frequent crowded areas or play contact sports are more likely to contract the infection. [Schools and dormitories are also known for infection spreads]. Individuals may contract MRSA by simply sharing items (hairbrushes, razors, clothes) with an infected individual. A hospices crowded nature also warrants its prevalence in hospitals. While a primary cause for the spread is related to patients vulnerability, MRSA is just as capable of infecting healthy individuals (though infections are more commonly seen in the wounded).

While MRSA spreads in other environments, spreads are the most predominant are in nursing homes, hospitals, and regular clinics, where MRSA infects the vulnerable- immunocompromised patients. Invasive surgical procedures also contribute to higher risks of contracting MRSA. Reason being that a pathway to inside the body is exposed.

When a patient has contracted MRSA, they are also more susceptible to contracting other infections as well. MRSA may lead to sepsis if left untreated. Additionally, unaffected carriers of MRSA can still spread the infection to others (MRSA Carrier- One who carries MRSA bacteria in their bodies, which has had no affect on them).

How do healthcare workers prevent the spread?

In hospitals, patients with MRSA are placed in isolation units, where person contact is limited. Any visitors or workers visiting those in isolation must wear protective gear and follow strict hygiene guidelines. All physicians take precautions dealing with patients in general, but exercise stricter regulations when dealing with isolation patients. When treating patients with MRSA, physicians wear masks, gloves, and gowns to protect themselves.

MRSA is notorious for its resistant nature and various antibiotics have been proposed to prevent further spread of the infection. As previously mentioned, some procedures involve surgical draining which help deal with surface level infections.

Despite the scare of MRSA, researchers and hospitals continue working diligently to prevent the spread. As minors, what can we do to aid our healthcare workers? We can start by conducting our own research, taking necessary precautions, educating our peers, and contributing to fundraisers, all towards helping discover a cure!

Works Referenced

DerSarkissian, Carol. “MRSA and Other Hospital Acquired Infections: Reducing Your Risks.” WebMD, WebMD, 8 Feb. 2020,

“For Patients.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 31 Jan. 2019,

McCue, Jack D. “The Contagious Patient.” Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd Edition., U.S. National Library of Medicine, 1 Jan. 1990,

“MRSA Infection.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 18 Oct. 2018,

Staff, Live Science. “MRSA Strikes More Hospital Patients, Study Finds.” LiveScience, Purch, 30 May 2013,

Pressure and Dehydration

If there’s one thing many are guilty of, it’s never drinking enough water. On surface level, It’s obvious dehydration does little justice, our bodies obviously require water to function and to maintain glowing skin! But what actually happens on the cellular level when we are dehydrated? 

First of all, our bodies are made up of water, where it’s 60 percent of body weight in males, and 50 percent in females. Water is vital. When dehydrated, the cell membranes become less penetrable, severely hindering the flow of nutrients and oxygen into the cell, and waste out. This waste accumulates and causes cellular damage. Cellular damage may lead to loss of function (of certain organs) and may lead to cancer if it aggregates.

The water which resides in our bodies falls into 2 categories, intracellular (inside cells) and extracellular (outside cells). The extracellular compartments include the water in the bloodstream and in the tissues (between tissue cells). Water may be transferred from intracellular to extracellular locations according to external conditions. The average person contains ⅔ of their water inside their cells. 

Each of these compartments consist of both water and salts. The salts, which are dissolved,  contribute to the osmotic pressure*.

Water Flow- Credit:

The osmotic pressure of the compartment is defined by the concentration of dissolved salts relative to other compartments. Osmotic pressure and concentration of salts are directly proportional ( greater concentration of salts, greater osmotic pressure). Under ideal conditions, there’s equilibrium of the osmotic pressure among the intracellular and extracellular compartments. However, in cases of dehydration, the concentration of salts decreases in one of the two compartments, prompting water to flow between the intracellular and extracellular compartments to re-equilibrate. 

There are 3 branches of dehydration, Isotonic dehydration, Hypotonic dehydration, and Hypertonic dehydration.

Isotonic dehydration refers to when there is a loss of water and the salt it contains. Salts are lost by vomit or diarrhea. Thus, there is a water depletion. To equilibrate the osmotic pressure again, some intracellular water flows into the extracellular compartment. Generally, they’re minor changes in osmotic pressure, but changes in water volume.

Hypotonic dehydration refers when body fluids contain a smaller concentration of dissolved salts than the cells. Since in osmosis, water follows its concentration gradient, water in the extracellular environment flow into the cells (because the cells have a higher concentration of salts). The cells swell, the membrane is stretched thin and can even lyse. Severe cases can even lead to cerebral edema.

Hypertonic dehydration is when the body loses more water than salts. Therefore, extracellular compartments possess a higher osmotic pressure, and water from the intracellular compartments flow out in order to balance the osmotic pressure. The cells shrink and lose their round shape. Cases of Hypertonic dehydration may lead to headache, weight loss, dry skin, and fatigue.

It is quite clear that dehydration has calamitous effects on our cells. Water shortages compromise cellular health and can cause severe health conditions. So hydrate, not only for external glow, but also to manage internal health!

Works Referenced

“Dehydration at the Cellular Level – MCEN4117 Dehydration.” Google Sites,

“Examples of Osmosis.” Diagrams Showing the Movement of Water through Cells,

O’Keeffe, Jillian. “What Happens to Your Cells When You Are Dehydrated?” Sciencing, 2 Mar. 2019,

The Editors of Encyclopaedia Britannica. “Dehydration.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 7 Dec. 2017,

Folding at Home

No, I’m not talking about laundry, no one ever likes talking about chores. I’m talking about the Folding@home project. Their goals have become principal currently, where there is a desperate need of protein research. With the COVID-19 scare, the Folding@home project has gained a ton of heat.

 The basis of the project relies on the concept of protein mis-folding, which leads to many disorders and diseases. The function of a protein depends solely on its shape, therefore, if a protein acquires the wrong shape, it will not be adept to perform its meant function. Protein folding occurs in 4 complex stages  (Primary, Secondary, Tertiary, and Quaternary), and thus proteins are prone to mistakes in the process.

4 Steps of Protein Folding. Credit: ATA Scientific

The project itself permits people at home to install a certain software and allow their computers (when not in use) to be utilized by scientists to conduct investigations on the proteins and contribute to research. The scientists use the simulations of the protein, being run on the software, in order to understand the protein’s moving parts.

First launched in 2018 for the sole purpose of the study and simulation of protein sequencing, it has been employed for research on Alzheimers disease, Ebola, Influenza, and even cancer. What about COVID-19?

The leaders of the Folding@home project have been working tirelessly to start more simulations of the COVID-19 proteins. Currently, the scientists have been simulating dynamics of the proteins in order to identify any possible cures.

The public response has been incredible with the project finally surpassing 1 million downloads. People from all over the world are installing the software and by allowing scientists to progress research, they are able to each contribute what they can to finding the cure for the pandemic. Hopefully with all the efforts made from Folding@home leaders and global contributors, researchers will be able to propose a cure sooner than later!

Works Referenced

“Diseases- Folding@ Home.” Folding@Home – Fighting Disease with a World Wide Distributed Super Computer.,

says:, V, et al. “Protein Folding: The Good, the Bad, and the Ugly.” Science in the News, 9 Jan. 2014,

Englander, S. Walter, and Leland Mayne. “The Nature of Protein Folding Pathways.” PNAS, National Academy of Sciences, 11 Nov. 2014,

What is Regenerative Medicine in Application?

Regenerative Medicine is the practice of replacing and regenerating human or animal tissues and organs to restore proper function to the impaired parts, usually damaged due to trauma, disease, or age. 

The Regenerative Medicine field relies on the practice of stimulating the body’s primary healing mechanisms to restore the damaged areas. In a situation where the body is incapable of healing itself, scientists attempt to grow healthy cells and tissues in labs to replace the impaired ones by implantation. The practice differs from the usual process of treating symptoms of certain conditions, but attempting to manually heal them.

How do these scientists grow healthy cells? The answer is stem cells! Stem cells are unique as their purpose is to grow into a variety of specialized cells which serve many vital purposes in the body (e.g. muscle cells, brain cells..). Stem cells are vital and are the primary aspect of Regenerative Medicine.

Stem cells can develop to serve many different functions!

There are 3 primary “concentrations” in Regenerative Medicine, Tissue Engineering, Cellular Therapy, and Artificial Organs/ Devices.

Tissue Engineering is a strategy used by practitioners where a biologically suitable scaffold is positioned and implanted at the area where the new tissue is to be regenerated. If the tissue is in the proper shape of the tissue being generated, the scaffold attracts nearby cells, resulting in the new tissue forming in the desired shape.

Cell Therapy centers around inserting harvested adult stem cells into damaged or diseased tissue to repair impaired organs under the ideal conditions. These stem cells may be collected from fat, blood, skeletal muscle, and the bone marrow (spongy tissue inside bone where blood cells are formed). Cord blood also provides a source of adult stem cells scientists are willing to use.

Artificial organs are the first resort when an organ fails. However, there are many challenges with obtaining a suitable donor. Such as availability and possible side effects when ingesting immunosuppressive drugs. To aid those with organ failures, scientists are working to engineer devices which can supplement the functions of the primary organs before failure.

Regenerative Medicine also allows researchers to understand how diseases develop, through the study of stem cell growth.

Works Referenced

Davies, S G. “Regenerative Medicine.” Regenerative Medicine – an Overview | ScienceDirect Topics, 2017,

Dunnill, Chris Mason & Peter, et al. “A Brief Definition of Regenerative Medicine.” A Brief Definition of Regenerative Medicine | Regenerative Medicine, 21 Dec. 2007,

Mao, Angelo S, and David J Mooney. “Regenerative Medicine: Current Therapies and Future Directions.” Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 24 Nov. 2015,

“Regenerative Medicine.” Nature News, Nature Publishing Group,

“Stem Cells and Regenerative Medicine: Failed Promises or Real Potential?” Medical News Today, MediLexicon International,

“What Is Regenerative Medicine?” Regenerative Medicine at the McGowan Institute,


What is Heterochromia?

Heterochromia means different (hetero-) colors (-chromia). It is a condition in which an individual’s irises are differently colored. (However the term may also be applied to skin and hair, not just irises)


  • “Iridis” and “iridium” refer to the iris of the eye. The iris is the thin, circular structure that surrounds the pupil and contains the pigment melanin, which gives our eyes their distinctive color.”

There are 3 different types of Heterochromia: 

  • Complete Heterochromia: One iris is a completely different color than the other
  • Partial/ Sectoral Heterochromia: A portion of the iris is a different color than the rest of the iris. One or both eyes can have partial Heterochromia 
  • Central Heterochromia: The rings or iris area around the pupil has a different color than the outer portions of the iris (like different colored rings!)
  • The 2 irises of a person are usually the same color, however, in Heterochromia  , the affected iris may be hypopigmented (hypochromic or lighter) or hyperpigmented (hyperchromic or darker)

Heterochromia iridis vs Heterochromia Iridum?
Heterochromia iridis is a specific condition where the iris in one eye possesses a different color than the iris of the other. Heterochromia iridum is a difference in color within the iris of one eye.


When or how does Heterochromia occur?

 Heterochromia can be either Congenital (present at birth) or acquired later in life (through an injury or a disease).


  • Present at birth or when an infant develops Heterochromia after birth
  • Majority of the time, kids born with Heterochromia   have no symptoms and their eyes function normally with no specific impairments to vision
  • Congenital Heterochromia is usually random or a result of intrauterine disease/ injury. Scenarios in which Heterochromia is inherited (hereditary) are rare yet possible.* 
  • Usually the eye color change occurs randomly in individuals with no family history of Heterochromia but can also occur as a result of a genetic mutation, as Heterochromia   is familial in cases of syndromes. 
  • Congenital Heterochromia is not rare, as it occurs in 6/1000 births. Congenital Heterochromia is usually unnoticeable as the difference in colors may be very little and is therefore unacknowledged in most situations.
  • The majority of the time, congenital Heterochromia is harmless and NOT associated with any systemic abnormality, however there are RARE cases where infant Heterochromia is associated with inherited* congenital syndromes such as:  
  • Horner’s syndrome 
  • Benign Heterochromia  
  • Sturge-Weber syndrome
  • Waardenburg syndrome
  • Piebaldism
  • Hirschsprung disease
  • Bloch-Sulzberger syndrome
  • von Recklinghausen disease
  • Bourneville disease
  • Parry-Romberg syndrome


Parry- Romberg Syndrome is a rare disorder in which the soft tissues and skin of half the face (usually the left) deteriorate over time. In relation to Heterochromia, the eyes generally become more sunken and can become hyperchromic or hypochromic. 

Here, the left side of the woman’s face has been affected. This can be seen how the cheeks have lost their previous shape, and that they eyes have not only become more sunken, but have also lightened.


  • Most cases of Heterochromia Iridis are mild, however, acquired Heterochromia may be due to underlying disease (most commonly due to eye disease). 
  • It may also be due to: 
  • Eye injury
  • Bleeding in the eye
  • Swelling, due to iritis or uveitis
  • Eye surgery
  • Fuchs’ heterochromic cyclitis
  • Acquired Horner’s syndrome
  • Glaucoma and some medications used to treat it
  • Latisse, a repurposed glaucoma medication used cosmetically to thicken eyelashes
  • Pigment dispersion syndrome
  • Ocular melanosis
  • Posner-Schlossman syndrome
  • Iris ectropion syndrome
  • Benign and malignant tumors of the iris
  • Diabetes mellitus
  • Central retinal vein occlusion
  • Chediak-Higashi syndrome 

Does Heterochromia require treatment?
Heterochromia is typically harmless and therefore does not require treatment. If Heterochromia  is present as a result of a condition, that condition is usually treated, not necessarily the difference in eye color.

Does Heterochromia cause any visual impairments?
Typically Heterochromia results in no visual impairments. Heterochromia is usually marked as an unprogressive condition not posing any concern. 

NEVUS in Heterochromia?

What is a Nevus? A Nevus is a birthmark or freckles that may occur on skin as well as IN the eye. A nevus can even occur in the iris! Since Iris Nevi (plural of nevus) are usually brown, they may be easily confused with Heterochromia, if occurring in an iris with a lighter pigment.

  • Nevi are benign and do not cause any discomfort. They typically remain the same size.
  • Though a Nevi appearing in a hazel, amber, green, or blue iris can be argued to be partial/ sectoral Heterochromia, the term Heterochromia is not used to describe the difference in colors since it is due to a nevus. 

Can Heterochromia occur in animals?

When I think of Heterochromia, I think immediately of playful huskies and fluffy white cats that you see on Instagram.

I was shocked to learn that horses, cows, and buffalo can have Heterochromia as well! Similar to humans, in most cases animals who have Heterochromia have inherited it from a parent (congenital). In fact, the prevalence of Heterochromia in a population can also signify a lack of genetic diversity and the likelihood for a population bottleneck to have happened in the past. But in terms of dogs and cats; Heterochromia is usually found in dog breeds such as…

  • Huskies 
  • Malamutes 
  • Great Danes
  • Dalmatians 
  • Border collies 
  • Shetland Sheepdogs
  • Dachshund 
  • Chihuahua
  • Shih Tzu 
  • Catahoula Leopard dogs
  • Australian

 Cat breeds which are also likely to have Heterochromia are…

  • Turkish Van
  • Japanese Bobtail
  • Turkish Angora
  • Khao Manee
  • British Shorthairs
  • Cornish
  • Munchkins

I was also amazed to learn that Heterochromia is not a native trait to wolves, the cover animal for beautiful multicolored eyes. The classic icy blue and mysterious brown! And that the only way possible for wolves to get the classic ice blue eye is when they have a genetic defect, such as a cataract. 

Heterochromia is an interesting condition which definitely sparked my curiosity. If you’d like to research more, check out these links:

The Killer Tomato

It’s hard to imagine an omelet without tomatoes or a burger without ketchup. It seems obvious that with ketchup being a popular condiment, that tomatoes must’ve been a stable for centuries. However, fairly recently has the tomato made its appearance into our diets. In Europe, following the late Middle Ages, tomatoes were considered deadly and were associated with witchcraft. Even in the late 1700s, the majority of Europeans feared the tomato, thinking it was poisonous. 

PHOTO BY | Michael R. Shaughnessy

The tomato is not poisonous, but after many European aristocrats died after eating them, the tomato acquired the nickname “Poison Apple”. Reality was that aristocrats weren’t dying due to tomatoes, but rather due to their utensils of choice. The wealthy used pewter plates, which contained high amounts of lead. Tomatoes have a relatively high acidity, (approximately 3.5- 4.8), therefore when placed on pewter plates, the fruit would leech lead, from the plate, causing lead poisoning. Unable to splurge on trendy items, the lower classes used wooden plates, and were less susceptible to poisoning than the wealthy.

At that time, no speculations were made about the content of the plates, and the tomatoes were deemed so poisonous that even a small bite could bring about catastrophe.

Even before the led poisonings, the tomato was infamous in Europe. It was considered a part of the family of poisonous Solanaceae plants which consist of high amounts of toxins, called tropane alkaloids. The tomato was referred to as a “deadly nightshade”, and associated with the family.

Solanaceae Family

While many believe the conjecture about pewter plates, Atlas Obscura points out flaws in the story. He claims that pewter plates weren’t common enough, tomatoes aren’t acidic enough, and lead poisoning gathers too slowly to lead to a poisoning in a singular meal. Atlas Obscura also brings forth theories that the unsatisfactory image resulted from its correlation with witchcraft.

Around this time period in Europe, (14-17th centuries), witchcraft was the primary subject of discussion. Through the centuries, thousands of people were killed or excommunicated under mere suspicion. Stories circulated about creations of witches brews, poisons, and their “flying ointments”. A common myth was that witches put this ointment on their broomsticks. These ointments consisted of mandrake, nightshade, and hemlock. With two of these ingredients having close correspondence with tomatoes, people began associating the tomato with witches.

This stigma around tomatoes persisted for centuries, but with the surface of science and technology, the fear of witchcraft started to fade. While many European kingdoms denounced tomatoes, civilizations in South America continued to consume them. Around the 1850s tomatoes began to infiltrate markets and became a stable.

And finally with the invention of Pizza in Naples, the tomato made its way into the common diet and its mysterious past was forgotten.