CLOSE

Forensic Scientists Devise a Better Method for Testing Crime-Scene Lipstick Stains

Femmes fatales, take note: Forensic chemists have found a better way to sample and test lipstick stains found at crime scenes. The researchers will present their findings tomorrow, March 14, at the national meeting of the American Chemical Society in San Diego, California. 

Over the years, scientists have used a number of different techniques for lifting and analyzing lipstick prints. The problem is that many of these methods are tedious, time-consuming, and expensive—which means they’re unlikely to be used in underfunded crime labs.

The new method focuses on analyzing the lipstick itself. With so many brands, colors, and formulas out there, matching a specific lipstick to a person of interest could significantly narrow down a field of suspects. To sample the evidence, the scientists wash the stained object with two solvents, which break down the lipstick’s oils and waxes. They then use a process called gas chromatography to identify the sample’s chemical formula. They then compare it to the unique formulas of 40 different brands of lipsticks.

These techniques are effective and cheap, requiring very little specialized training. To date, the researchers have only tested the process on paper and cloth, but hope to eventually expand to glass and other surfaces. 

This is very cool science, although it may not see too much use. In an email to mental_floss, lead researcher Brian Bellott, of Western Illinois University, admitted that “lipstick is one of the less common trace evidences found at a crime scene.” 

Yet because it's less common, perhaps that makes it more noticeable—which is all the more reason for all you lipstick-wearing criminals to cover your tracks. Don’t say we didn’t warn you. 

Header image from YouTube // American Chemical Society

Original image
Hulton Archive/Getty Images
arrow
science
6 Radiant Facts About Irène Joliot-Curie
Original image
Hulton Archive/Getty Images

Though her accomplishments are often overshadowed by those of her parents, the elder daughter of Marie and Pierre Curie was a brilliant researcher in her own right.

1. SHE WAS BORN TO, AND FOR, GREATNESS.

A black and white photo of Irene and Marie Curie in the laboratory in 1925.
Irène and Marie in the laboratory, 1925.
Wellcome Images, Wikimedia Commons // CC BY 4.0

Irène’s birth in Paris in 1897 launched what would become a world-changing scientific dynasty. A restless Marie rejoined her loving husband in the laboratory shortly after the baby’s arrival. Over the next 10 years, the Curies discovered radium and polonium, founded the science of radioactivity, welcomed a second daughter, Eve, and won a Nobel Prize in Physics. The Curies expected their daughters to excel in their education and their work. And excel they did; by 1925, Irène had a doctorate in chemistry and was working in her mother’s laboratory.

2. HER PARENTS' MARRIAGE WAS A MODEL FOR HER OWN.

Like her mother, Irène fell in love in the lab—both with her work and with another scientist. Frédéric Joliot joined the Curie team as an assistant. He and Irène quickly bonded over shared interests in sports, the arts, and human rights. The two began collaborating on research and soon married, equitably combining their names and signing their work Irène and Frédéric Joliot-Curie.

3. SHE AND HER HUSBAND WERE AN UNSTOPPABLE PAIR.

Black and white photo of Irène and Fréderic Joliot-Curie working side by side in their laboratory.
Bibliothèque Nationale de France, Wikimedia Commons // Public Domain

Their passion for exploration drove them ever onward into exciting new territory. A decade of experimentation yielded advances in several disciplines. They learned how the thyroid gland absorbs radioiodine and how the body metabolizes radioactive phosphates. They found ways to coax radioactive isotopes from ordinarily non-radioactive materials—a discovery that would eventually enable both nuclear power and atomic weaponry, and one that earned them the Nobel Prize in Chemistry in 1935.

4. THEY FOUGHT FOR JUSTICE AND PEACE.

The humanist principles that initially drew Irène and Frédéric together only deepened as they grew older. Both were proud members of the Socialist Party and the Comité de Vigilance des Intellectuels Antifascistes (Vigilance Committee of Anti-Fascist Intellectuals). They took great pains to keep atomic research out of Nazi hands, sealing and hiding their research as Germany occupied their country, Irène also served as undersecretary of state for scientific research of the Popular Front government.

5. SHE WAS NOT CONTENT WITH THE STATUS QUO.

Irène eventually scaled back her time in the lab to raise her children Hélène and Pierre. But she never slowed down, nor did she stop fighting for equality and freedom for all. Especially active in women’s rights groups, she became a member of the Comité National de l'Union des Femmes Françaises and the World Peace Council.

6. SHE WORKED HERSELF TO DEATH.

Irène’s extraordinary life was a mirror of her mother’s. Tragically, her death was, too. Years of watching radiation poisoning and cancer taking their toll on Marie never dissuaded Irène from her work. In 1956, dying of leukemia, she entered the Curie Hospital, where she followed her mother’s luminous footsteps into the great beyond.

Original image
iStock
arrow
Food
Researchers Pinpoint the Genes Behind the Durian's Foul Stench
Original image
iStock

Durian is a popular fruit in parts of southeast Asia. It's also known for having the most putrid, off-putting odor of any item sold in the produce section. Even fans of durian know why the fruit gets a bad rap, but what exactly causes its divisive scent is less obvious. Determined to find the answer, a team of researchers funded by "a group of anonymous durian lovers" mapped the fruit's genome, as reported by the BBC.

The study, published in the journal Nature Genetics [PDF], contains data from the first-ever complete genetic mapping of a durian fruit. It confirms that durian's excess stinkiness comes from sulfur, a chemical element whose scent is often compared to that of rotten eggs.

Analysis of the fruit's chemical makeup has been done in the past, so the idea that sulfur is a major contributor to its signature smell is nothing new. What is new is the identification of the specific class of sulfur-producing genes. These genes pump out sulfur at a "turbocharged" rate, which explains why the stench is powerful enough to have durian banned in some public areas. It may seem like the smell is a defense mechanism to ward off predators, but the study authors write that it's meant to have the opposite effect. According to the paper, "it is possible that linking odor and ripening may provide an evolutionary advantage for durian in facilitating fruit dispersal." In other words, the scent attracts hungry primates that help spread the seeds of ripe durian fruits by consuming them.

The revelation opens the door to genetically modified durian that are tweaked to produce less sulfur and therefore have a milder taste and smell. But such a product would likely inspire outrage from the food's passionate fans. While the flavor profile has been compared to rotten garbage and dead animal meat, it's also been praised for its "overtones of hazelnut, apricot, caramelized banana, and egg custard" by those who appreciate its unique character.

[h/t BBC]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios