Close
DIY

Cholera cookies, delicious or gross?

February 21, 2012 1Comment
TCBS is a selective medium for Vibrio cholerae, but this cookie didn't make me sick!

 

Every December the Georgia Tech School of Biology has a holiday party with one of those never ending gift swaps.  Most of the presents are silly, and you never know if you are going to wind up taking home a ramen noodle cookbook or a puka shell necklace.  This year, every time I had a present I liked it was stolen and ulitmately I was left with the decision of whether to open the last unwrapped gift or make the game go on for another round.  I took the last gift, ending the game, and to my delight found it was filled with hilarious homemade science cookies!  Maria Nellessen, an Emory University biology major doing research in Dr. Brian Hammer’s lab at Georgia Tech made the cookies.  I recently asked her about herself and the cookies.  Read on to learn more about this budding microbiologist with a sweet tooth!

A beaker, an erlenmeyer flask and a test tube. All edible!

 

1) I understand that you go to Emory and are graduating this semester. What are you studying and what are you planning on doing after graduation?

Yes, I am a senior biology major at Emory.  I have spent this year in Brian’s lab at Tech doing research in order to write and defend a thesis, ultimately graduating from Emory with honors.  I was initially planning on pursing a Ph.D. in Molecular Genetics immediately after graduation, however, I recently decided to act on my desire to obtain a medical education.  Part of the reason I found and fell in love with science is because of all its implications in medicine.  I truly want to make a contribution to the medical field using a strong scientific background.  Therefore, I am planning to enter a MD or a MD/PhD program in the fall of 2013.  In the meantime, I hope to find a job to keep me occupied (maybe I should add cookie making to my CV).

This cookie looks like an agarose DNA gel. Hope there's no ethidium bromide in there!

 

2) What inspired you to make decorated cookies depicting one of the most dangerous bacteria in the world, the causative agent of cholera? What about the other cookies? Could you describe the mice?

To promote eating cholerae. Okay, not really.  Actually, I was in a grant writing course at Emory with a mix of both science and humanities students, and we were asked to give a creative presentation based on the project we were working on.  Since not everyone in the class was a biologist, or scientist for that matter, I was reminded of my first time learning about microbiology in my intro course and I distinctly remembered the proud feeling that came along with doing a streak plate for isolation.  To this day, I get that same proud feeling when I come into the lab the next day to see my plates with isolated colonies (success…I’m a scientist!).  I really wanted to share that feeling with my classmates, but I was limited by the fact that I couldn’t allow them to work with bacteria.  So I thought I would teach them the streak plate method and let them enjoy “results” through a cookie.

I started getting practice making the streak plate cookies by making them for science related events (such as lab meetings and for my microbiology students).  I really didn’t want to go out and buy anything for the Christmas party (because I’m a poor college student), so I decided to make some science cookies, even branching out to new designs in efforts to brighten a fellow science nerd’s day.  Choosing to do a TCBS plate with Vibrio cholerae was easy because I work with V. cholerae in the lab and we use this green media (called TCBS) that causes V. cholerae to turn a bright yellow on the plate.  In a way, V. cholerae is actually quite pretty on the plate and I wanted to represent that in a cookie.  The other designs were just me thinking of other scientific designs I could do, as well as searching the internet for other ideas.  Sure enough, other people also make science cookies  I got a lot of inspiration from Not So Humble Pie (she makes streak plate cookies too!).  While I don’t research on mice, I thought they were cute, so I gave them a try.

Uh oh, looks like one of those mutations is lethal!

 

3) How did you make the cookies? Do you have any tips for the novice baker?

For the record, I do not in any way consider myself a baker.  I don’t even have the tools that most bakers have, which would actually make decorating these cookies a whole lot easier.  I’m not going to pretend I have a secret recipe (let’s be honest here…I’m in college!).  For the cookie, I just follow the roll-out cookie recipe on a sugar cookie mix (I prefer Krusteaz) and use a cup to cut out the circle shape. Since I only made a few of the other designs, I just cut them out with a knife.  Then I throw together a powder-sugar based frosting to decorate my cookies.  I know….no big secret, right?  Anyone can make and decorate cookies.  Each time I make them, I may modify something to perfect my “recipe,” but getting the signature cookie takes time and practice.  The good thing is that your mess-ups are usually still edible and delicious!

It must be hard to make a cookie flagellum.

 

4) Have you ever made any other strangely decorated cookies or do you have plans to?

My busy lifestyle rarely leaves time for me to bake for fun, but sometimes I’ll come across something (usually science-related) and think to myself “that’d be a cute cookie.”  I honestly have thought about perfecting recipes and publishing them along with information/instructions as I often do when I make my streak plate cookies for students.  When I made a batch of cookies for the Christmas party, I attempted to make a V. cholerae bacterium but it ultimately looked like some kind of squash.
I’m sure my future medical education will provide me with plenty of opportunities to make all sorts of weird (and probably disturbing to most people) cookies.  I’d love to try to create a complete skeleton, where each bone is a cookie.
Perfect technique!

 

– So, it turns out making weird cookies is not as hard as I thought.  Maybe I’ll make some T cell cookies this weekend!
Tags:
0Likes
Jennifer Leavey
About Author

I love to write about science, sing about science, teach about science and DO science! My favorite animal is Apis mellifera, favorite color is 440nm and favorite solvent is EtOH.

Leave a comment

You May Also Like

DIY, today i learned (til)
Let’s Go!: Costa Rica
DIY, today i learned (til)
Berkeley grads grow mushrooms for cash – legally!
DIY, today i learned (til)
The Primary Colors are What?!
DIY
Raindrop Cake, Not a Cake?

Your journey starts here! Let’s talk!

ThemeRex © 2026. All rights reserved.
  Timothy Durham was convicted of rape when a test showed his DNA genotype matched the DNA recovered from the crime scene. Eye witnesses testified that Durham was in a different state at the time of the incident, but he wasn’t exonerated from his 3000 year sentence until follow up DNA analysis showed that the preliminary forensic analysis used in the trial was misinterpreted (Thomas et al.). DNA testing serves an invaluable part in our criminal justice system, but it comes with complications and bias that can lead to wrongful convictions and misinformed juries.  

Background:

Forensic genetics aims to identify the origin of a biological sample. It can be traced back to Karl Landsteiner who discovered human ABO blood groups. With blood groups, suspects could be eliminated based on their blood type. For example, if a suspect had type A blood and there was type B blood left at the scene by the perpetrator, the investigators could rule out the suspect. Unfortunately, the reverse didn’t work. If the suspect and perpetrator both had the same blood type, it can’t be concluded that the suspect was guilty. Blood identifiers evolved into 8 distinct categories which improved the ability to eliminate suspects, but could only conclude that (if the system matched) it might be the perpetrator or this person might be related to the perpetrator (Jobling and Gill). The field evolved in the 1980s with the discovery of Minisatellites, lines of repetitive DNA that don’t encode proteins. Minisatellite patterns in DNA create what we know today as the DNA fingerprint, and it has a much higher accuracy rate than previous methods (Augustyn et al.). Around the same time, a breakthrough for victims of sexual assault was discovered. In the case of assault, bodily fluids of both the victim and the assaulter can get mixed. A process called differential lysis was created which could selectively increase the concentration of sperm in a fluid sample thereby allowing for accurate DNA testing (Jobling and Gill). Forensics evolved to use single-locus probe testing after several years because of its ease of interpretation. It looked at specific minisatellites that had high variability between subjects. This was the first DNA-based method to be used in a criminal investigation. Two murder homicides from several years apart were connected using DNA evidence. The evidence was then used to exonerate an innocent man, and the guilty party was found when he tried to evade mandatory DNA testing for all men in the small town. His guilt was then reinforced when the DNA profiles matched, and he gave a confession (Jobling and Gill). Finding DNA at a crime scene doesn’t guarantee that you’ll find a murderer. There are issues with non-pure samples and limited samples that make DNA work difficult, and accreditation of facilities and new techniques and take time (Jobling and Gill).  

Subjectivity of DNA Interpretation:

In a 2009 publication, the National Academy of Science discusses the possibility for subjective influence in lab based forensics. The interpretation bias happens in complex cases where, for example, there could be a mixture of DNA. A study published in 2011 looked specifically at this issue. A gang rape happened in Georgia, and the mixture in DNA from the case was used to prosecute one suspect after another suspect took a plea bargain to testify against him. With DNA mixtures, there are three possible conclusions: suspect excluded, suspect cannot be excluded, and inconclusive. If the suspect is excluded, it means that there’s little to no possibility that his DNA is part of the sample. If the suspect cannot be excluded, it means that there’s a possibility that his DNA is part of the sample. In the trial, the DNA examiners who knew the context of the case concluded that the suspect being prosecuted could not be excluded. The 2011 study gave the DNA evidence from this case and the DNA profiles of the suspects to 17 forensic examiners. These examiners had no context of the case, and they all worked independently. Of the 17, only 1 came to the same conclusion (suspect cannot be excluded) as the examiners who knew the context of the case. Twelve of the 17 concluded that the suspect who was prosecuted and convicted had no relation to the DNA found in the sample. Not only does this show that subjectivity occurs due to the context of the case, but the 17 examiners came up with different findings based on their past experiences meaning that not all DNA analysis is objective. Some organizations like the Scientific Working Group on DNA Analysis Methods say that quantitative statistical evidence should be presented with every categorical conclusion, but the US doesn’t require this (Dror and Hampikian).

False Positives:

There are two categories that cause wrongful identification in a DNA report: coincidental matches and false positives. Coincidental matches are DNA matches between two unrelated people. The probability of these matches is about 1 to 500,000 for white individuals and about 1 to 350,000 for black individuals. This small probability of coincidental matches makes people feel confident in DNA evidence. False positives, on the other hand, are matches between DNA and test DNA that result from issues in the forensics lab. There have been multiple cases of forensics labs accidentally switching victim and suspected rapist DNA which lead to convictions that were later overturned when the lab realized the error. There are also cases of misreading or misunderstanding a sample. In a case from 1993, a man was convicted of rape because someone interpreted a mixed sample of victim and perpetrator DNA as an individual sample. The conviction was again overturned. To prevent false convictions, retesting DNA is allowed, but it’s not an efficient solution. Many people are pushing for statistical information on the probability of false positives, so that the jurors can make accurate judgements based on DNA evidence (Thomas et al.).  

Conclusion:

DNA analysis is a useful tool for the criminal justice system, but subjectivity can be an issue in forensic testing. To combat wrongful convictions, there are organizations like The Innocence Project who use DNA testing to free the innocent, but reformed forensic testing standards should be put in place to prevent subjectivity and to ensure juries are correctly informed during trials. https://www.innocenceproject.org/    

Citation:

Augustyn , Adam, et al. “DNA Finerprinting.” Encyclopedia Britannica , 26 Apr. 2018, www.britannica.com/science/DNA-fingerprinting#ref153186. Dror, Itiel E., and Greg Hampikian. “Subjectivity and Bias in Forensic DNA Mixture Interpretation.” Science & Justice, vol. 51, no. 4, 2011, pp. 204–208., doi:10.1016/j.scijus.2011.08.004. Jobling, Mark A., and Peter Gill. “Encoded Evidence: DNA in Forensic Analysis.” Nature Reviews: Genetics, vol. 5, no. 10, Oct. 2004, pp. 739–751., doi:10.1038/nrg1455. Thompson, William C, et al. “How the Probability of a False Positive Affects the Value of DNA Evidence.” Journal of Forensic Sciences, vol. 48, no. 1, Jan. 2003, pp. 1–8., doi:10.1520/jfs2001171.