About Me

Heidi the Biologist:

S. aureus cells.
 Arjes, et al, 2014 - Failsafe mechanisms couple cell division
and DNA replication in Bacteria.
PhD work: I earned my PhD at Washington University in St. Louis in Petra Levin's lab. There, I studied the bacterial cell cycle and identified a link between bacterial cell division and subsequent rounds of DNA replication in Bacillus subtilis and Staphylococcus aureus. In particular, I characterized a previously unknown block in the replication of DNA initiation following blocks in cell divisions and I found that cells that undergo prolonged blocks in either DNA replication or cell division exit the cell cycle, where they remain metabolically active but can no longer divide and form progeny.

I also performed a biochemical characterization of the bacterial cell division protein FtsZ in Escherichia coli. FtsZ is a protein that can connect to other FtsZ proteins like a stack of legos. I studied how two proteins fit together during this stacking process using a mutant protein that does not fit together well (imagine the lego top is a bit mis-shapen and does not fit well into the bottom of the next protein unit). I identified secondary mutations that helped the protein fit together well enough to function, knowledge that helped us understand the molecular mecanisms of this protein's function.

A photo of B. subtilis biofilms I took in lab.

Postdoc work: After my PhD, I joined the laboratory of KC Huang as a postdoctoral scientist. A postdoctoral scientist (or "postdoc") is a scientist that has their PhD and is doing semi-independent research in a lab to prepare them for future endeavors like running their own lab (as a PI or Principle Investigator), industry, or many other options. In KC's lab, I am investigating how bacteria live, grow, and communicate in diverse communities called biofilms. Bacteria are single cell organisms and can live on their own or can live in communities where they interact with each other and can develop individual functions and take on different roles. I am also exploring how the soil bacterium B. subtilis responds to stresses such as oxygen depletion. I am constantly amazed by all aspects of microbiology and all the organisms that live in and around us! 

Presenting my work at the Stanford postdoctoral research symposium
Source: Stanford SURPAS Instagram account

Heidi the Knitter:

Knitting with friends at Cafe Zoe in Menlo Park
I spend a lot of my spare time knitting and crafting. If you could not tell by the overarching theme of this blog, I love everything crafty, especially knitting and crocheting! I began designing knitting patterns in 2012 and you can find my patterns on Ravelry (Heidi Arjes designs) or Craftsy (Craftimism). My favorite designs are my #knityourPhD items where I design a hat to represent my friends' PhD theses. I also love designing #ScienceKnits. With all of my science knitting designs, I try to write a blog post describing the science behind the knitting as a form or science outreach to knitters and others who follow my blog.

Heidi the Knitting Sciencist (or Sciencing Knitter):

I endeavor to do science outreach to non-scientist knitters and the general public. In particular, I am the co-organizer of a knitting program at a local elementary school that consists of students from underserved backgrounds. I also do knitting outreach to scientists. I personally know that knitting makes me a better scientist by alleviating stress and encouraging my creative juices. I have taught scientists and non-scientists alike how to knit and hope to encourage the continuation and expansion of this craft.

If you would like to contribute to my science/knitting outreach programs, please contact me at craftimism[at symbol].gmail.com.

Happy Crafting!


  1. I am making hats for the 4/22 March. On the downloaded patterns, above the charts where the (love) SCIENCE pattern is, it says 41 sts to repeat. Should be 42. Love your designs!

    1. Thanks for letting me know! I'll fix it in version2.

  2. Hi Heidi! The DNA double helix hat is the one for me! Which color yarn did you use for your designs? I don't see where it's listed anywhere so I thought I'd ask. Thanks so much for the patterns.

    1. I used Deborah Norville everyday soft yarn in peacock for most of the march for science hats. It is available online from Joann.com, unfortunately not in stores. I like that it is anti-pilling and very soft for an acrylic. :)

  3. Hi Heidi! The DNA double helix hat design is the one for me. What color yarn did you use? I didn't see where it was listed anywhere so I thought I'd ask. Thanks for the patterns!