When June Almeida wrote a paper about a new kind of virus she’d discovered, scientists reviewing her paper told her that she’d made a mistake. June, who was one of the world’s most skilled electron microscope technicians, would soon prove them wrong. She had, in fact, photographed and identified an entirely new kind of virus, which she and her colleagues later named coronavirus.
Born in Scotland in 1930, June was a bright student, but she didn’t have enough money to go to the university. When she was sixteen, she left school and went to work as a laboratory technician at a hospital, where she looked through a microscope for the first time. June proved extremely talented at histopathology, which involves studying slides of human tissue and identifying diseases.
She eventually went to work in a lab in London, got married, and moved to Canada where she learned to use electron microscopes, which are powerful enough to magnify viruses. Although she didn’t have a college degree, June quickly became so talented at microscopy that researchers she worked with made her a co-author on some important scientific papers about the structures of viruses.
A British professor of virology named A.P. Waterson convinced June to return to England, where she was awarded a doctorate of science degree. Now called Dr. Almeida, June became the first person to visualize the rubella virus, which causes the German measles. She also pioneered a technique called immune electron microscopy, which uses antibodies to clump viral particles together so that they’re easier to see.
When a colleague sent her a sample of an unidentified virus to look at with her electron microscope, June thought it looked similar to the one she’d tried to publish a paper about before. This time people believed her when she said that she’d discovered an entirely new kind of virus. She and her colleagues named this new family of viruses coronaviruses, for the crown-like halo that was visible around the viral particles in June’s photographs.
Later in her career, Dr. Almeida published important papers on a bird respiratory virus and the hepatitis B virus. She also came out of retirement in the 1980s to help take images of HIV, which causes the disease AIDS.
Thanks to the work of June Almeida and her colleagues, scientists were recently able to identify the SARS virus and the SARS-CoV2 virus that causes COVID-19 as coronaviruses. What Dr. Almeida and her colleagues discovered about the structure of these and other viruses still helps scientists develop vaccines and drugs to keep humans and animals safe from them today.
June Almeida pioneered a microscopic technique which used Y-shaped proteins called antibodies to make viruses clump together. In this lab, use sculpting clay and toothpicks to make model viruses and antibodies to illustrate the clumping process called agglutination. Small children should be supervised when using toothpicks and skewers. 1 Roll several pieces of sculpting clay into small balls and put each piece onto the sharp end of a skewer or on the stick end of a cut cotton swab. Fig. 1. 2 Stick two toothpicks into each sculpting clay ball to form a Y-shaped object. Each Y-shape you make represents an antibody. Antibodies are proteins made to recognize and bind to objects your body recognizes as foreign, such as bacteria, viruses, and fungi. Fig. 2. 3 Create ten to twenty viral particles out of sculpting clay. Look up an image of the type of virus you want to represent and copy it as well as you can, or just make tiny balls covered in spikes to represent coronavirus. Fig. 3. 4 Lay the antibodies and viral particles out on a tray or baking sheet. Fig. 4. 5 Use the antibodies to capture the viral particles, attaching one virus at a time to a toothpick. Fig. 5. 6 To agglutinate the viruses, attach some toothpicks to the same viral particles. Fig. 6. 7 Neutralize the virus by attaching each particle to an antibody. CREATIVE ENRICHMENT Viruses come in many shapes and sizes. Look up information about viruses that cause common human illnesses, such as colds and influenza, to learn more about them, including how they spread and how vaccines are made. THE BIOLOGY BEHIND THE FUN Our bodies are constantly at war with microbial invaders. Certain viruses can hijack our cells to make millions of copies of themselves and make us sick. Proteins called antibodies are some of our body’s best defenders against these invisible foes. Antibodies help the body kill foreign particles by tagging them for destruction by white blood cells. In addition, they make viral particles clump together, so they are not able to enter human cells. Scientists call the clumping of viral cells by antibodies “agglutination.” The parts of a foreign objects recognized by antibodies are called antigens. Antibodies are Y-shaped and the Fab (fragment antigen-binding) region on each arm is the part that binds to invaders, such as viruses. An antibody’s stem is called the Fc (constant) region. More than one antibody at a time can attach to a viral particle, and each antibody can attach to a different viral particle with each arm. This allows the antibodies to agglutinate the viral particles, making it easier for white blood cells to identify them, gobble them up and destroy them using a process called phagocytosis (see Lab 9). In most cases, large clumps of antibody-coated virus cannot enter cells to cause infection.CORONAVIRUSES/AGGLUTINATION
MATERIALS
SAFETY TIPS AND HINTS
PROTOCOL
18.206.76.160