Michael Wu ’20 researches Single Domain Antibodies at Youan Hospital in Beijing, China

The Single Domain Antibody (sdAB), also known as VHH, is engineered from camelids’ heavy-chain antibody. Different from conventional antibody, composed of two heavy chains and two light chains, camelid heavy chain antibody does not contain light chains. With smaller molecular weight, sdAB is more stable than conventional antibody and able to reach otherwise inaccessible epitopes which cause molecular mechanisms of disease. As a result, further studies are needed for pharmaceutical and biomedicine, and future prospects are promising.

My internship this summer is working on the potency of four different VHHs binding selectively to a specific antigen. Given with four different VHH templates, I intend to test their sequences by transforming each template constructed with expression vector pCold into DH5α cells and later carry out protein expression in E. coli BL21. In everyday experiment, I start working around 8:30 in the morning and spend most of my time working in the lab with the help of either my supervisor or other graduate students. We have a three-hour “lunch break”, which is quite nice. I spend most of the time reading some paper about other scientists work on sdAB (or take a nap for an hour). Usually, I will be able to finish my work by 5:30 and report to my supervisor for what I have done so far and also the next day plan.

Until this point, I have done the first half of my experiment by having 3 out 4 sequences successfully tested. These three sequences will be used for later protein expression. During the past one and half months, I have practiced lab skills, such as Polymerase Chain Reaction (PCR), Gel Electrophoresis, Transformation, etc. I also learnt pertinent knowledge by reading paper and articles during experiment waiting times (which can get tedious sometimes). However, things are not always as expected. I have experienced two times of unexpected failures in my experiment. One was when I tried to construct my templates with expression vector pCold. I accidentally added the wrong enzyme, which failed to cut the region I intended to. Luckily, I did not have to restart everything, and my supervisor was very tolerant to my careless mistake. The other one

Fig 1. Comparison of Conventional Antibody with Camelid Heavy Chain Antibody
https://www.biocat.com/proteomics/custom-antibody-services/single-domain-antibody-services

happened at the end of this first half experiment. I only had 3 out of 4 sequenced correctly. I spent extra weeks and lab fundings to redo this one part of experiment hoping to get a satisfied result. Unfortunately, I did not get it. Though frustrated, I discussed with my supervisor and other graduate students on the reasons why causing this unexpected outcome. With their help, I found out that the problem was actually with that one template given to me. My supervisor agreed to carry the rest of three sequences to the next part my experiment. Besides those two “failures”, I ran into many other unexpected problems and detected multiple flaws within my experiment. Since unexpected and unfavorable conditions seem inevitable, learning how to deal with them is as crucial as leaning new knowledge in order to perfect my work next time and survive better in the future lab life, which surly can get more and more challenging.

By the end of my internship, I hope to finish all my lab work and acquire all the data needed for my thesis. I will report my work to my thesis advisor, discussing about my thesis direction and plan. All my work during this summer will be included in my thesis paper. By the time of undergraduate conference, I hope I will have a chance to introduce my project this summer to the whole Whitman community and inspire other BBMB students who care about Immunology, which I believe that it is the future “cure-all” for human.


Experiences like Michael Wu’s are made possible by the Whitman Internship Grant, which provides funding for students to participate in unpaid internships at both for-profit and non-profit organizations. To learn how you could secure a Whitman Internship Grant or host a Whitman intern at your organization, click here or contact Assistant Director for Internship Programs Mitzy Rodriguez

 

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