Tag Archives: DNA

DNA Supplements May Be Secret of Longer, Healthier Life

Tired? Forgetful? Feeling old before your time? Forgetful? Maybe it’s your DNA—or lack of it.

DNA-based alternative medicine is one of the fastest growing health fields today. Combining the marketing strengths of science, health, and religion, it’s no wonder that researchers are stocking the shelves and lining their pockets with a variety of DNA supplements and diagnostics. Here are some of the most exciting products and findings.

Puritans Pride DNA Supplements May Be Secret of Longer, Healthier LifeA diet rich in DNA—and its molecular cousin, RNA—is correlated with improved performance across a wide range of activities, both physical and mental, and could help stave off the effects of aging. Results of a bold new study from Kashkow University’s School of DNA and Medicine, expected to begin next year, were announced yesterday. They have been called a “breakthrough” and a “game-changer” by some of the leading scientists on the proposed study.

Dr. Cyrus Tosine, a lead researcher on the study, said that supplemental DNA and RNA could be of particular benefit to patients suffering from low energy, poor muscular strength and stamina, pain and stiffness in the joints, forgetfulness, and an inability to concen

The general result should come as no surprise, Tosine says. “DNA and RNA operate at the core of life,” he notes. “Supplemental RNA and DNA promote cellular integrity.” Independent research does confirm that the absence of RNA and DNA negatively affects cells’ ability to survive, which could be considered a form of integrity. Further, Tosine pointed out, nucleic acid activity is halted by cell death. “And when your cells die, you die,” he observed. DNA, he concludes, is related to aging. “QED.”

The research uses a sophisticated new analytical technique called “meta-meta-analysis,” which pools the results of many studies that pool the results of many studies. This gives the method such great statistical power that it can find a correlation between any two variables. Thus, it is already possible to say with confidence that DNA intake is positively correlated with all major indicators of health—and negatively correlated with a variety of diseases.

The research was hailed by the plastic surgeon Dr. Vincent C. Giampapa, M.D., F.A.C.S., one of the most prominent members of this exciting new field. “DNA is our life source,” he confirmed.
Recognizing a potential market in anxious new mothers and covering both the scientific and religious bases, one company is developing a line of infant probiotics called “DNA Miracles.” Their advantage, she says, is that “with DNA Miracles Probiotics Extra, you can rest easy knowing that you’re providing your child one of the most complete children’s probiotic and prebiotic formulas on the market today.”

Magnum DNA DNA Supplements May Be Secret of Longer, Healthier LifeAthletes, too, are recognizing the benefits of upping their intake of what double helix co-discoverer Francis Crick called the “secret of life.” DNA is being mixed with branched-chain amino acids (BCAAs)—some of the building blocks of protein—to create potent muscle-building supplements. An Australian company offers a patented “coded DNA amino acid BCAA,” which contains “the perfect coded DNA amino acid sequence.” The sequence, of course, is not only proprietary but classified, lest it fall into the hands of an evil mastermind determined to clone a race of LeBron Jameses crossed with Olga Korbuts.
DNA Repair Cream DNA Supplements May Be Secret of Longer, Healthier Life

Other work centers on DNA repair, a well-established field of science. Dr. Giampapa, M.D., F.A.C.S., is author of over 700 studies showing the benefits of improving DNA with his patent formulas. “Just improving a small percentage of our total DNA can make a major difference in the quality of our health, well being and longevity.” Dr. Giampapa, M.D., F.A.C.S. says. Science is still learning how small a percentage can make a major difference, and what in the name of Watson and Crick “improving” your DNA could mean.

Where does it come from?

Not all DNA is created equal. Some of the highest quality DNA is extracted from freeze-dried lamb placenta, say some experts. Dr. Rad Bitchen, of Woohoo Pharmaceuticals, explains: “Studies have supported that sheep placenta is one of the richest source of nutrients.” Two capsules of their DNA/RNA supplement contain over five miles of nucleic acid—500 times the recommended daily allowance, set last week by Bitchen himself.

wohoo lamb placenta dna e1396366055653 DNA Supplements May Be Secret of Longer, Healthier LifeAnimal rights’ groups, however, have protested the freeze-drying of lambs. A spokesorganism for PETNA (People for the Ethical Treatment of Nucleic Acids) notes that even in a wool coat, the young ovines must get the shivers during the process.

PETNA and others promote the use of “cruelty-free” DNA. Woohoo’s DNA also contains “marine protein,” which, Bitchen insists, is “like wicked delicious.” He emphasizes that no Marines are harmed in his process. Another company, Anathema Nucleoceuticals, makes a line of DNA-based condiments. Their biggest seller is Guano Butter, made from bat guano and olive oil. Anathema’s literature says it is delicious on whole grain toast or Ak-Mak crackers. Yet some object to DNA collected from any higher animals.

“No nuclear membrane, no problem,” says Ariadne Fishnet, of Portland, Oregon. Fishnet is a freelance farmer of sustainable E. coli, a bacterium normally found in the human gut. Extracting the DNA from bacteria is completely painless, she says, even though it eviscerates the organism. “At first we used only wild-caught bacteria, because that sounded better. But it turned out to be economically unpractical, as well as kind of gross. We have a new model of sustainable bacteria farming. All our bacteria are free-range, non-GMO, and antibiotic-free.”


Swanson RNA DNA DNA Supplements May Be Secret of Longer, Healthier LifeNevertheless, not everyone is convinced of the value of megadoses of DNA. Dr. Ron Swanson, of the University of California at Boulder, believes that prokaryotic nucleic acid is at best worthless and perhaps damaging. “The highest quality DNA comes from steak and cigars,” he says. Further, he continues, it is not the quantity but the “balance” between DNA and RNA that provides the key to health. “Our studies show that RNA/DNA imbalance is the root cause of a variety of symptoms,” he said. “If you feel fatigue, weakness, muscle and joint stiffness, memory loss, or lack of ability to concentrate, restoring the correct balance has been shown absolutely equivocally to sometimes help stuff,” he said.

Drs. Kathleen, Elaine, and Mary, of the Natural Healthcare Ministries Research Center and Salon in Credulity, Wisconsin, believe that massive doses of DNA and RNA constitute a “one size fits all” approach that is out of harmony with what makes us all special. DNA medicine should be personalized, “Because we’re all people,” noted Mary. “Except for the sheep,” Elaine chimed in. “Yea but they’re frozen,” Mary replied. “Shut up,” snapped Elaine.

Kathleen continued, “Homeopathic energy DNA testing is based on the principle that everything in nature, even substances that do not move, gives off energy as a vibration.” Any foreign substance entering the body, she said, may have an irritating effect on the body, “because of the vibrations.” Their method, Sound Therapy On Nucleic acid Energy Depletion (STONED), is to “ test this energy (your DNA) by testing your hair.” They then correct the vibrations using a variety of cellular actualization techniques. They also offer styling and manicures, half off on Tuesday mornings.

In spite—or perhaps because— of its controversial nature, DNA medicine is clearly on the rise. All experts agree on one point: everyone should limit their intake of food that contains no DNA. Examples include processed sugar, high-fructose corn syrup, lard, and Chicken McNuggets.




A Piece of DNA – Olivia Judson

Recommended reading:

Lovely essay from Olivia Judson on the cytosine she came across while sorting through her father’s possessions–part of the original Watson & Crick model that Horace somehow got his hands on, presumably through Crick. I remember hearing from Horace about that cytosine, though I never chanced to see it.

With that model, in a way, DNA became real. It acquired form humans could perceive. It gained a legible structure, it became an image. It took on an identity, on the way to becoming an expression of our own identity.

A Piece of DNA – NYTimes.com.

23andMe, FDA, and the history of hype

Yesterday I and seemingly everyone else interested in genomes posted about the FDA letter ordering the genome diagnostics company 23andMe to stop marketing their saliva test. FDA treats the test as a “medical device, because “it is intended for use in the diagnosis of disease or other conditions or in the cure, mitigation, treatment, or prevention of disease, or is intended to affect the structure or function of the body.” The company first issued a bland, terse statement acknowledging the letter and then company president Anne Wojcicki signed a short post affirming the company’s commitment to providing reliable data, promising cooperation with FDA, and reasserting her faith that “genetic information can lead to better decisions and healthier lives.” (I say she “signed” it because of course we have no way of knowing whether she composed it and she’s no fool: surely the text was vetted by Legal.) In other words, the company followed up with a bland, less-terse response, carefully worded to reassure customers of the company’s ethical stance and core mission. Reactions to the FDA letter range from critics of the company singing “Hallelujah!” to defenders and happy customers are attacking FDA for denying the public the right to their own data. The 23andMe blog is abuzz and, hearteningly, a few sane souls there are trying to dispel misinformation.

I am doing history on the fly here. If journalism is the first draft of history, let’s take a moment to revise that first draft—to use the historian’s tools to clear up misconceptions and set the debate in context as best we can. The history of the present carries its own risks. My and other historians’ views on this will undoubtedly evolve, but I think it’s worth injecting historical perspective into debates such as these as soon as possible.


We must be clear that the FDA letter does not prohibit 23andMe from selling their test. It demands they stop marketing it. The difference may not amount to much in practice—how much can you sell if you don’t market your product?—but the distinction does help clarify what is actually at stake here. FDA is not attempting to instigate a referendum on the public’s access to their own DNA information. They are challenging the promises 23andMe seems to make. This is, in short, not a dispute about access, but about hype.

The company seems to promise self-knowledge. The ad copy for 23andMe promises to tell you what your genome “says about you.” “The more you know about your DNA,” they trumpet, “the more you know about yourself.” On one level, that’s perfectly, trivially true: your genome does have a lot to do with your metabolism, body structure, how you respond to disease agents, and so forth. The problem is, we as yet know very little about how it all works. The 23andMe marketing exploits a crucial slippage in the concept of “knowledge,” which FDA correctly finds misleading. In short, the marketing implies a colloquial notion of knowledge as a fixed and true fact, while the science behind the test is anything but.

Historians and other scholars of science have thought a lot about the concept of scientific knowledge. In 1934, Ludwik Fleck wrote about the “genesis and development of a scientific fact,” namely the Wasserman test for syphilis. It is a pioneering classic in a now-huge (and still growing) literature on how scientific facts are created. Science claims to gather facts about nature and integrate them into explanations of natural mechanisms. A moment’s reflection reveals that very few scientific facts last forever. Most, perhaps all, undergo revision and many are discarded, overthrown, or reversed. They are historical things, not universal truths. A surprisingly small amount of what I learned in science courses 20 and 30 years ago is still true. As that great philosopher of science John McPhee wrote, “science erases what was previously true” (Oranges, p. 75). Because scientists search for universal, timeless mechanisms, they easily slip into language suggesting that they discover universal, timeless truth. But there is uncertainty, contingency, malleability built into every scientific fact.

This goes double for genome information. The 23andMe product, like every genome test, provides probabilities of risk, not mechanisms. Probabilities are messy and hard to understand. They carry an almost irresistible tendency to be converted into hard facts. If you flip a coin 9 times and it comes up heads every time, you expect the next flip to come up tails. And if you get heads 49 times in a row, the next one has got to be tails, right? Even if you know intellectually that the odds are still 50:50, just like on every previous flip. You can know you have a particular gene variant, but in most cases, neither you nor anyone else knows exactly what that means. Despite the language of probability that dots the 23andMe literature, their overall message—and the one clearly picked up by many of their clientele—is one of knowledge in the colloquial sense. And that is oversell.

Human genetics has always been characterized by overstatement and hype. In the early 1900s, the rediscovery of Mendel’s laws persuaded many that they now understood how heredity works. Although every scientist acknowledged there was still much to learn, prominent students of human heredity believed they knew enough to begin eliminating human defects through marriage and sterilization laws. We now view such eugenic legislation as almost unbelievably naive. Combine that naivete with race, gender, and class prejudice and you obtain a tragically cruel and oppressive eugenics movement that resulted in the coerced sterilization of many thousands, in the US and abroad—including, of course, the Nazi sterilization law of 1933, based on the American “model sterilization law,” which culminated not only in racist forced sterilization but euthanasia.

Human-genetic hype hardly ended with the eugenics movement. In 1960s, as human diseases were finally being mapped to chromosomes, it seemed transparent that if a chromosomal error that produces an individual with an XXY constitution feminizes that individual (which it does), then an extra Y chromosome (XYY) must masculinize. Such “super-males,” data seemed to suggest, were not only taller and hairier than average, but also more aggressive and violent. It was, for a while, a fact that XYY males were prone to violent crime.

The molecular revolution in genetics produced even more hype. When recombinant DNA and gene cloning techniques made it possible to try replacing or augmenting disease genes with healthy ones, DNA cowboys hyped gene therapy far beyond existing knowledge, promising the end of genetic disease. The 1995 Orkin-Motulsky report acknowledged the promise of gene therapy but noted,

Overselling of the results of laboratory and clinical studies by investigators and their sponsors…has led to the mistaken and widespread perception that gene therapy is further developed and more successful than it actually is.[1]

Soon after this report was published, Jesse Gelsinger died unexpectedly in a gene-therapy trial, patients in a French gene-therapy trial for adenosine deaminase (ADA) deficiency unexpectedly developed leukemia, and the gene-therapy pioneer W. French Anderson was arrested, tried, and convicted on charges of child molesting—in other words, abusing and overestimating his power over the children whose health was entrusted to him. The risks of failing to heed warnings about genetic oversell are high.


Like gene therapy, genome profiling has great promise, but the FDA letter to 23andMe is a stern reprimand to an industry that, like gene therapy and the entire history of human genetics, blurs the line between promise and genuine results.

The current controversy over commercial genome profiling has two qualities that distinguish it as particularly serious. First, unlike previous examples of overselling human genetics, it is profit-driven. The “oversell” is more literal than it has ever been. Although 23andMe presents as a concerned company dedicated to the health of their clientele, they are also—and arguably primarily—dedicated to their stockholders. In a for-profit industry, oversell is a huge temptation and that risk needs to be made transparent to consumers.

Second, the 23andMe test is being sold directly to individuals who may not have any knowledge of genetics. The tendency to convert risks into certainty is higher than ever. The knowledge they sell is a set of probabilities, and further, those probabilities are not stable. The consumer may not—indeed probably doesn’t—appreciate how much we know, how much we don’t know, and how much we don’t even know we don’t know. The company claims to be selling knowledge but in fact they are selling uncertainty.

In a characteristically insightful and clarifying post, the geneticist (and 23andMe board member) Michael Eisen doubts whether the 23andMe test will ever meet FDA’s definition of a “medical device.” It is not an MRI machine or a Wasserman test. It’s something new. Adequate regulation of products such as the 23andMe genome profile will require rethinking of what exactly the company is marketing.

Putting this controversy in context, then, illustrates another critical risk: the risk of failing to acknowledge the uncertainty underlying the science. In some sense, the more we learn, the less we know.


[1] Orkin, S. H., and A. Motulsky. Report and Recommendations of the Panel to Assess the NIH Investment in Research on Gene Therapy.  Bethesda, MD: National Institutes of Health, 1995.


We’ve been pretty serious for a while, which always makes me a little edgy. And “tattoos” or some version thereof continues to be one of the biggest search terms for this blog. So, to raise the font size of “tattoos” in the tag cloud, I’ve put together a gallery of eye candy.

In their 1994 book, The DNA Mystique, Susan Lindee and Dorothy Nelkin write that “habitual images and familiar metaphors…provide the cultural forms that make ideas communicable.” The double helix is the scientific icon of our age—much like the Bohr atom was during the Cold War. Putting it on your body identifies you with science, with biotechnology, with life. It is also just a stone beautiful image, which works in a line, say down your spine, wrapped around a biceps or ankle, or curving sinuously just about anywhere. The best collection of science-themed tattoos of course is Carl Zimmer’s “Science Tattoo Emporium.” Many of these were borrowed from his archive, so a big hat-tip (tat-hip?) to him. I have the hardcover version Science Ink prominently displayed on my coffee table. Others drawn from elsewhere around the web. Click the picture to open the original url.

tree dna DNA Ink

A DNA riff on the Darwinian image of the “tree of life.” But it of course also reminds me of the eugenics tree…

eugenics tree DNA Ink

DNAfoot DNA Ink

Foot tattoos are hard. Here’s a cute rendition of unwinding DNA that flows nicely with the anatomy.

Invisible DNA Tattoo by LucidPetroglyphs666 DNA Ink

Not the best execution of the image (no major and minor grooves), but a neat black-light effect that reminds me of fluorescent labeling.

metallic DNA 3D Tattoo fairylandtattoos.com  DNA Ink

Just. Wow.

circular DNA Ink

All right, I admit I’m wondering whether this represents bacterial DNA (and is therefore circular).

biomech1 2sleeve DNA Ink

An interesting “biomechanical” visual effect.

DNA Stomber DNA Ink

Here artist Jason Stomber has woven the double helix into a full sleeve.

twinsisters 1024x595 DNA Ink

Clever use of the DNA icon by a pair of twin sisters. Of course, when they line them up, they become prokaryotes.



23andMe, myself, and I

Here is the new ad from 23andMe that will begin airing shortly on cable TV*:

Genomics is going mainstream and the best news is first that it’s real simple and second that it’s all about me.

Let’s take the most obvious first: the “me” meme. Of course this relates to the company name, but the ad takes me to a new level. It makes “you” your DNA. I give them points for a couple of qualifiers — it “helps” make me who I am, one character says. But the overall message is that you are your genes.

It also exploits the meme of egocentrism. Nearly everything today seems to be all about me. Memoirs are the hottest genre of nonfiction. We have a magazine called “Self.” One of the most common themes on commercial websites is to have a “My [company name]” area, which usually just means they have your personal information to use to sell you more stuff. There’s even a “.me” internet domain, which they advertise “is all about you.” Who isn’t curious about himself? I’m the most interesting topic in the world! And 23andMe will tell me about my true inner nature for just $99.

One element of personalized medicine, then, is narcissism. Another, more noble, element is individuality. No one is more committed to his individuality than I am—but I’m also wary of its dark side: selfishness. I am struck by the single reference to future generations (“what I will pass on to my kids”). Again, this is a two-sided coin. In the Progressive era, the literature on genetic medicine emphasized family and community. There isn’t a hint of that here. On the one hand, then, the ad is free of the eugenic message of controlling human evolution. On the other, it’s relentlessly selfish. Most likely, the reason for staying away from issues such as family, community, and responsibility is that it enables them to steer way wide of abortion. This ad is about me, not my kids and not the future. That’s actually a new and rather radical development in genetics. 

A persistent theme in popular literature from the 19th century to the 21st, is that hereditary information provides certainty. This despite the fact that one of the signal insights from genomics is how uncertain its results are. Genetic medicine today is all about probabilities, and to make informed decisions based on our genetics we have to understand how probability works. The ad works against this principle, promising certainty where there is only chance. “Now, I know” says one woman. No, you don’t. Now, you have a sense of risk—not certainty. This is a dangerous over-simplification.

double helix 23andMe, myself, and I

Simplified double helix from Watson and Crick’s 1953 paper.

This sense of simplicity is also carried in the graphics. Note how there’s hardly a double helix in it. “Your” DNA is reduced to circles, dots, and lines. They move and whirl entertainingly and there’s just enough suggestion of complexity to carry the message that you can’t understand “you” without them‚ 23andMe. If DNA becomes as central to identity as companies such as 23andMe want to make it, this ad suggests that its iconic image may fade. Even the stripped-down ribbons and bars version is simply too complex for TV.

karyotypedowns 23andMe, myself, and I

An early karyogram (of Down syndrome) from the 1960s.

image001 23andMe, myself, and I

A comprehensive chromosome map from UCSF.

MyDNA 1024x562 23andMe, myself, and I

Screen shot from 23andMe commercial. Her “DNA” is those two colorful cylinders by her ear.

Most of the genetic “knowledge” promised is simple enough to be carried in the one- and two-syllable words that dominate mass-market media. Genetic medicine, stuffed as it is with Latinate and Greek words, is a tough sell in that market, but the ad pulls it off. At 0:21 we hear the longest word in the ad: “hemochromatosis.” The speaker pauses after the second syllable, to suggest empathy with viewers who get hung up on such terms. According to the Mayo Clinic website, hemochromatosis is indeed usually inherited, is rarely serious, is most common in men, and is the most common genetic disease in Caucasians. The ad script gives this word to a black man. Thus, one of the ad’s subtle messages is to erase racial differences—even differences supported by scientific evidence. It’s a commonplace in TV ads nowadays to feature men and women of many hues, but the 23andMe ad takes it a step further.

Another theme of the commercial is the way it suggests communities based around biological identities of health and disease. Once, our primary identities were with those who lived near us, or shared our work or hobbies or politics. But politics has become personal, our communities are digital, and our identities center around health. The sociologist Nikolas Rose calls this “biological citizenship.” The 23andMe website features forums where members who share particular mutations or risks can discuss diets, lifestyle habits, child-bearing decisions–or their pets, if they wish. They are communities based around health. The ad sends the message that race, class, and gender are no longer our defining social themes: what matters now is health and disability.

We hear so much about the importance of educating the public about their biology as a key component of contemporary personalized medicine, but in this ad that biology is reduced to bumper-sticker-like phrases about this circle “saying” I will have blue eyes and that line segment “saying” I have a risk of this or that disease. Learning about me will be fun, easy, and inexpensive. Thank goodness I can mail off a C-note, spit in a cup, and in a few weeks get a report that simplifies it all in language I can understand. The ad ends with a rainbow of people chanting “Me. Me. Me.” It’s the “Om” of the 21st century.


*h/t to Bob Resta for sending the link to the ad, and to Shirley Wu (@shwu) for a tweet that showed me that the hemochromatosis passage was too terse in yesterday’s version. I’d been wanting to add something about biological citizenship and Shirley’s comment suggested a way to do it.




DNA spoofing

Okay, there could not be a more apt title for a Genotopia post. This conceptual art piece is scientifically silly, almost frivolous, but it makes a serious point (I know!): the prospect of genetic surveillance is creepy. I love the notion of “genetic ambiguity.”


Sexuagenerian Double Helix

It’s not “DNA day.” That’s in April–fittingly, the date of publication. Today is double helix day.
On this date in 1953, Watson and Crick solved the structure of DNA. What better day to lay to rest a few myths about it?

crick and watson Sexuagenerian Double Helix

Another, more candid shot from Barrington Brown’s roll.

1) It sparked a scientific revolution.
The double helix caused a stir in the scientific fields closest to Watson and Crick’s work: X-ray crystallography and bacteriophage genetics. But it took several years for the structure and it’s most important implication–the copying of the genetic material–to be confirmed. True, Time Magazine sent a photographer to Cambridge to shoot for a possible feature. From it came Barrington Brown’s famous photo of the duo before a mock-up of the structure, with Crick brandishing of all things a slide rule at it and smirking at the silliness, and Watson gazing, baffled, up at his hero. But they pulled the story. The double helix didn’t become world-famous until after the Nobel Prize, in 1962. the revolution did come, then, but it reverberated from the fusillade of discoveries from molecular biology of the fifties and early sixties: the double helix, the Meselson-Stahl experiment, the operon, and, perhaps most importantly, the genetic code.

Photo 51 Sexuagenerian Double Helix2. Watson stole Photograph 51.
The beautiful photograph of the diffraction pattern of b-form DNA taken by Rosalind Franklin and Raymond Gosling famously provided crucial evidence that enabled Watson and Crick to solve the structure. Watson obtained the image without Franklin’s knowledge. But the image was given by Gosling to Maurice Wilkins, who gave it to Watson. As correspondence recently published in The Annotated and Illustrated Double Helix makes clear, the administrative relationship between Wilkins and Franklin was murky. Franklin reasonably assumed she was independent of Wilkins; yet he apparently was technically if not in practice her supervisor. Watson may well have exploited these ambiguities; he was intensely competitive for that time. But theft is such an ugly word.

3. Watson and Crick were racing against Linus Pauling.
Pauling seems to have been genuinely surprised to learn that he was racing for the double helix against the oddball duo from Cambridge. Watson probably felt a sense of competition with the great pioneer of structural chemistry, but it takes two to race. Watson thought he was racing against everyone, with the possible exception of Crick. The real competition was with the group at King’s College London–Wilkins and Franklin.

4. The Double Helix is a history of the double helix.
Watson’s best-selling book is a literary-historical memoir. It is an important source for historians, but it must be read with care. The book was shaped by personal goals, politics, and literary strategies as much as by historical events. It is naive to treat it as a literal account of what “really happened.”

In the past sixty years, DNA has become the foundation of biomedicine, an emblem of innateness, the most famous molecule in history. It promises more revolutions to come, in healthcare and in our sense of identity. Let us celebrate it by demystifying it. History, too, can be salutary.

Read On

Comfort, Nathaniel. “‘Novel Features of Considerable Interest’.” Science 339, no. 6120 (2013): 648-48. doi:10.1126/science.1233356.

Gingras, Yves. “Revisiting the “Quiet Debut” of the Double Helix: A Bibliometric and Methodological Note on the “Impact” of Scientific Publications.” J Hist Biol 43, no. 1 (2010 2010): 159-81.

Creager, Angela N. H., and G. J. Morgan. “After the Double Helix: Rosalind Franklin’s Research on Tobacco Mosaic Virus.” Isis 99, no. 2 (2008 2008): 239-72.

de Chadarevian, Soraya. “Portrait of a Discovery : Watson, Crick, and the Double Helix.” Isis 94 (2003 2003): 90-105.