For the 9^th consecutive year, the field of science has taken this day to celebrate women in the STEM industries and their achievements. The representation of women in STEM is climbing, however it remains low, with estimates claiming women make up only around 26% of the workforce. By celebrating the accomplishments of women in these fields, we hope to encourage more girls to enter the world of science and engineering and challenge the adversity women in STEM all too often face.

In honour of International Day of Women and Girls in Science 2024, we’ve looked at some of the most important achievements in the life sciences. Some of the names you’ll be familiar with, others may be new. We’ll travel to Ancient Greece where we will learn about the first female science writer and surgeon, before coming back to today to recognise some of the most groundbreaking innovations in medicine. For far too long the door to a career in the life sciences has been all but closed for women, as you will discover in this article. Yet some of the discoveries and triumphs over adversity we’ll look at are arguably some of the most important achieved by humanity.

Metrodora

In Ancient Greece, it was believed that science was derived directly from the gods. This meant, like other divine disciplines, women were not allowed to practice medicine. However, such a technicality did not stop our first heroine of science. Before her exploits in Greece, Metrodora was likely born and educated in Egypt where men and woman were equals, unlike much of the ancient world. In fact, some believe Metrodora to be an alias of the famous Cleopatra VII, Queen of Egypt. There is some debate about when Metrodora lived; some say between 200-400 CE, others claim it was more likely to be during the 7^th century CE. The name Metrodora is particularly fitting for a woman of her accolades. In Greek, metro can be translated as womb, and dora means gift.

Metrodora was the author of a textbook, making her the first female science writer, spanning 2 volumes and 108 chapters entitled On the Disease and Cures of Women, in which she describes in detail her theories and findings on the topics of female health and the reproductive system. She is thought to have devised treatments for sterility, infections of the female reproductive system, menorrhagia (heavy periods) as well as a method for determining sexual abuse in women. Not to be limited by writing and medicine, Metrodora was also a surgeon, cited as removing dead embryos to save the lives of mothers who miscarried, removing cancers of the breast and uterus and was even among the first to perform cosmetic surgery. Metrodora reconciled this with her Hippocratic duty to help women who had been abused through aesthetic facial and breast reconstruction and the restructuring of the hymen of women who had suffered this fate.

Her pioneering work, however, was quite nearly forgotten forever as she was largely overlooked by her contemporaries. But thankfully, some of her texts are preserved in the Laurentian Library in Florence. Metrodora’s commitment to medicine and female health is summed up perfectly in the opening words of her text, “some of them are intricate to treat and others are fatal, by these notes we will recognise each one”.

Elizabeth Blackwell (1821-1910)

Elizabeth Blackwell was always destined to shake the status quo. Her father, Samuel, was a Quaker and an antislavery activist. Among her siblings are Henry, an abolitionist and women’s suffrage supporter; her sister, Emily, who followed Elizabeth into medicine; and her sister-in-law, Antoinette Brown Blackwell, who was the first female minister in mainstream Protestantism.

She was inspired into a life of medicine after a close friend had confessed embarrassment of her treatment by male doctors and suggested she’d have been more comfortable if attended to by a female physician. After a series of rejections from numerous medical schools, Elizabeth was finally accepted to Geneva College, New York. However, this acceptance was intended as a practical joke. Not to be discouraged, Elizabeth proved them all wrong, graduating top of her class in 1849 and becoming the first woman to graduate medical school. Dr Blackwell then practiced in London and Paris and was one of the first advocates for the importance of hygiene in medicine, noting that male doctors frequently failed to wash their hands, which led to the spread of epidemics.

In 1851, Elizabeth made the trip back to New York where discrimination was still rife. Once again, her persistence led to the opening of the New York Infirmary for Women and Children in 1857 with Dr Emily Blackwell and Dr Marie Zakrzewska. This institution was a haven for women who needed medical treatment but were often too poor to afford it, and for female physicians struggling to get work in the field. Among her laurels, she played a role in the inception of the National Health Society, established in 1871, which aimed to spread knowledge of public health, and is considered the predecessor to the National Health Service.

Marie Curie (1867-1934)

Marie Curie is among the most famous of the women in science, so we won’t spend too much time on her life and accomplishments here. However, its impossible to have the discussion without mentioning her invaluable contribution to science. In often poor laboratory conditions with worse equipment, she, and her husband Pierre Curie, made some pivotal discoveries including the isolation of polonium and radium. Marie Curie developed techniques to separate radium from radioactive residues which allowed it to be studied extensively and eventually, its use as a therapeutic agent.

In 1903, Marie and Pierre Curie were awarded half of the Nobel Prize for Physics for their work on spontaneous radiation. Then, in 1911, Marie Curie was given a second Nobel Prize, this one for chemistry, for her work on radioactivity. In recognition of her groundbreaking work leading to novel cancer therapies, the charity Marie Curie was named in her honour, immortalising her and her contributions to the field.

Gerty Cori (1896-1957)

Here we find another woman whose name outshines that of her husband, Carl, with whom she collaborated for most of her scientific career. Gerty graduated from medical school in 1920, along with her husband, before they emigrated to America in 1922. Here, they initially delved into the fate of sugar within the animal body, exploring the impacts of insulin and epinephrine. They made groundbreaking discoveries, including the demonstration of glycolysis in tumours in vivo. Their research on carbohydrate metabolism evolved from whole animal studies to experiments on isolated tissues, and eventually to tissue extracts and isolated enzymes, including some in crystalline form. In a pivotal moment in 1936, they isolated glucose-1-phosphate, known as “Cori ester,” and linked its formation to the activity of phosphorylase, which plays a crucial role in the breakdown and synthesis of polysaccharides. This discovery paved the way for the enzymatic synthesis of glycogen and starch in vitro.

Their research extended into the realm of hormone action mechanisms, with several studies focusing on the pituitary gland. They observed significant changes in rats that have had their pituitary gland removed, including a marked decrease in glycogen and a drop in blood sugar levels, accompanied by an increased rate of glucose oxidation. Further investigations into the effects of hormones on hexokinase revealed that certain pituitary extracts could inhibit this enzyme both in vivo and in vitro, while insulin was found to counteract this inhibition.

Beyond their groundbreaking research, the Cori’s served as an endless source of inspiration to their peers in the vibrant hubs of biochemical research they led. Their contributions to The Journal of Biological Chemistry and numerous other scientific journals have left an indelible mark on the field, showcasing their innovative work and collaborative spirit throughout their careers.

Gertrude Belle Elion (1918-1999)

Gertrude provides us with another tale of the triumph over adversity. After graduating with a degree in biochemistry in 1937, she failed to obtain a graduate position because she was a woman. After roles in laboratories and teaching, she joined the Burroughs Wellcome Laboratories in 1944 and became the assistant to Dr George Hitchings. Over the following 40 years, the pair were successful in the development of a vast array of new drugs and treatments. Much of their success is attributed to their methods. At the time, normal practice is best described as trial and error. However, Hitchings and Elion studied and intimately understood the difference between normal and pathogenic biochemistry, allowing them to envision and create targeted treatments for, to name just a few, leukaemia, urinary-tract infection, gout, malaria and viral herpes.

Although she never achieved her doctorate, in 1967 Elion was promoted to Head of the Department of Experimental Therapy, where she remained until her retirement in 1983. But Elion didn’t let a silly old thing like retirement get in her way. She remained at the Burroughs Wellcome Laboratories as a Scientist Emeritus and Consultant, including overseeing the development of azidothymidine, the first drug used to treat AIDS. Elion also became a Research Professor of Medicine and Pharmacology at Duke University, working with medical students in the field of tumour biochemistry and pharmacology, while continuing to write and lecture. Gertrude B. Elion passed away in 1999, bringing an end to a happy and fruitful career as one of the most influential women in science.

Rosalind Franklin (1920-1958)

Rosalind Franklin, another well-known name and one synonymous with the discovery of the DNA double helix, was an exceptional scientist whose meticulous work in X-ray crystallography laid the groundwork for one of the 20th century’s most significant scientific discoveries. Franklin graduated from Cambridge University in 1941, where she initially delved into the study of coal, gases, and carbon compounds, significantly contributing to the understanding of the molecular structures of these materials. Her early research not only showcased her exceptional skills in physical chemistry but also set the stage for her pioneering work in biology.

In 1951, Franklin joined King’s College London, where she was tasked with improving the X-ray crystallography unit. It was here that Franklin embarked on her most famous work: the study of the structure of DNA. Using her expertise in X-ray diffraction techniques, she captured Photograph 51, a critical piece of evidence revealing the helical structure of DNA. This image was crucial in identifying the double helix structure, although her contributions were not fully acknowledged until after her death.

Franklin’s research extended beyond DNA to the study of viruses, making significant strides in understanding the polio virus and the tobacco mosaic virus. Her work in virology, much like her work on DNA, was pioneering, employing her crystallography skills to uncover the detailed structure of viral particles. This work provided valuable insights into how viruses replicate and infect cells, contributing to the broader field of virology and paving the way for future research in virus structure and function.

Despite facing considerable challenges as a woman in a predominantly male scientific community, Franklin’s contributions were profound. Her relentless pursuit of scientific truth, combined with her exceptional experimental skills, left a legacy in the fields of chemistry, virology, and genetics. Beyond her scientific achievements, Franklin is remembered as a trailblazer who paved the way for future generations of women in science, demonstrating the critical role of perseverance and dedication in the pursuit of knowledge.

Françoise Barré-Sinoussi (1947-)

When discussing women who changed science, it’s impossible not to mention Françoise Barré-Sinoussi. She was born in Paris in 1947 and attended university there. Her passion for science saw her skip class to work at the Pasteur Institute, participating in investigations of retroviruses that caused leukaemia in mice. Although, this didn’t seem to affect her exams scores, and she received her PhD in 1974.

Françoise Barré-Sinoussi is hailed as the woman who discovered the viral cause of the AIDS epidemic. In 1982, the Pasteur Institute was approached by a virologist from a hospital in Paris, seeking help in identifying the cause of a worrying new epidemic. In a mere 2 weeks, Barré-Sinoussi, and her colleagues at the Pasteur Institute, isolated and grew a retrovirus from a biopsied lymph node of a patient at risk of AIDS. The virus, later named HIV-1, was found to be the cause of the AIDS epidemic.

Barré-Sinoussi has been contributing to virology research ever since, including areas such as the function of the host’s innate immune defences in managing HIV/AIDS, the elements contributing to the transmission of HIV from mother to child, and traits enabling a select group of HIV-positive individuals to restrain HIV replication without the need for antiretroviral medications. In 1992, Barré-Sinoussi was appointed Head of the Biology of Retrovirus Unit, renamed the Regulation of Retroviral Infections Unit in 2005.

However, Barré-Sinoussi didn’t stop at the science. She became a prominent activist for public education about AIDS prevention and helped to establish centres for diagnosing and treating AIDS around the world. In 2006, Barré-Sinoussi was elected to the International AIDS Society (IAS) Governing Council and served as president of the IAS from 2012-2016.

Jennifer Douda and Emmanuelle Charpentier

Most people have heard of CRISPR-Cas9. But many aren’t aware that we have women to thank for this scientific innovation. In 2012, Jennifer Douda (left) and Emmanuelle Charpentier (right) discovered the ingenious CRISPR-Cas9 technology – a groundbreaking tool in genetic engineering, which holds the promise of revolutionising medicine and biology. By enabling precise editing of the DNA in the cells of living organisms, CRISPR-Cas9 could lead to cures for genetic disorders, enhance crop resistance to pests and diseases, and advance our understanding of complex genetic conditions. It offers the potential to correct genetic defects, combat infectious diseases, and even manipulate traits in plants and animals, paving the way for significant advancements in therapeutic treatments, agricultural productivity, and the study of genetics. This discovery saw both women share the Nobel Prize in Chemistry in 2020.

We’ve only looked at a subsection of science, but one where the importance of the innovations and discoveries is felt by people every day. The scientists we’ve discussed here are only a small sample of the inspirational women that have graced the STEM field. We hope that by elucidating some of their work, we can inspire more girls and women to pursue a career in STEM. Careers in this field are challenging and rewarding, perfect for those with a curious mind and those in whom discovery sparks delight.