A guide to a PhD in Life Sciences in Europe : Part 4 - How to determine your 'area of interest'?

You are about to finish your master’s degree soon. You already know people around you who have gone to Europe for a PhD. You have an idea about various universities offering a PhD program. You are already fantasizing walking down the cobblestoned alleys of a typical European town. Now it’s time for you to shortlist the universities and start applying. You start using the internet and Google throws up loads of information about various universities in Europe offering a PhD. You are overwhelmed and confused with this. Moreover, almost every application procedure wants you to write a statement of purpose (SOP). The principal investigators of research groups want to know your motivation behind applying to their labs. They want to understand what is your area of interest, which skills you have, and how your presence will benefit their ongoing research. If you are aware of your interests and have a good career plan, things are easy for you. However, this is not the case with most students. Most students lack the exposure to the various research fields of biological sciences, and thus, are unable to decide what interests them most. Some students, however, are well-read, have a good theoretical understanding of various topics, but do not understand what exactly does it mean by doing research in a particular field of life sciences. The whole thing results into either a failure in getting a PhD position or ending up in a wrong place. To avoid this mess, it is very important to clear the confusion in your head and decide what exactly you wish to do.

First of all, let’s have an overview of some of the important areas of research in the field of life sciences. I have avoided the textbook definitions and tried to make it as simple as I can. The list is not exhaustive.

·      Biochemistry – It is a study of chemical processes occurring within living organisms. It involves studying biomolecules, metabolic reactions and their regulation. This field mainly deals with carbohydrates, lipids, and proteins. The laboratory techniques that exploit the chemical nature of biomolecules are termed as biochemical techniques. Chromatography and electrophoresis are two major biochemical techniques.

·     Molecular biology and genetic engineering – It is a study of nucleic acids and the processes involved in the central dogma of life. The research questions associated with DNA replication, transcription, translation, and the regulation of these processes are grouped under the field of molecular biology. Genetic engineering or recombinant DNA technology is a set of techniques used for manipulating DNA sequence. Although it is considered as a separate field, it is based on the concepts of molecular biology.

·     Biophysics – It is the study of how laws of physics govern the processes occurring in living organisms. It involves studying interactions between biomolecules, how proteins fold, how chromosomes are organized, etc. Techniques such as spectroscopy and microscopy, which are based on the physical properties of biomolecules are included amongst biophysical techniques.

·      Structural biology – It is all about determining the structure of biomolecules, mainly proteins. Since the structure of a molecule is its physical property, the field of structural biology is considered as a subset of biophysics. This field involves techniques such as X-ray crystallography and NMR.

·     Bioinformatics and computational biology – Bioinformatics is the use of computer technology to organize and study biological information. For example, creating and maintaining genomic sequence database, looking for homologs of a particular protein by surveying the database, and other similar approaches. On the other hand, computational biology involves developing novel computational tools for addressing biological questions. For example, writing a computer program for an automated analysis of microscopic images. Computational biology requires a thorough knowledge of computer programming. The tools of bioinformatics and the advances technique of obtaining biological data (DNA sequencing, metabolite identification, protein sequencing, etc.) have given rise to specialized areas of study such as genomics, proteomics, metabolomics, metagenomics, etc.

·    Cell biology – It is the study of processes that occur in a single cell. For example, intracellular trafficking, cell movement, cell division, functions of cell organelles, and other similar topics.

·      Microbiology – It is the study of micro-organisms, mainly bacteria. Quorum sensing, biofilm formation, antibiotic resistance, bacterial chemotaxis and motility are some of the important research areas in the field of microbiology.

·       Immunology – It is the study of the immune system.

·     Infection biology – This field involves studying the biology of the infecting agent in the context of the infection process. For example, studying the processes occurring during infection by the malarial parasite or understanding how Vibrio cholerae causes the symptoms of cholera. This field also explores the possible strategies for prevention and treatment of infectious diseases.

·      Evolutionary biology – This field studies different processes related to evolution, such as origin of life, speciation, natural selection, sexual selection etc. These processes are now also being studied at a molecular level using advanced techniques.

·     Systems biology – It is the study of systems of biological components which may be molecules, cells, organisms or even species. It involves quantitative measurement of behaviors of the components under study.

·   Synthetic biology – It is, a) the design and construction of new biological parts, devices, and systems and b) the re-design of existing biological systems for useful purposes. For example, engineering bacteria for a targeted drug delivery or rewiring the metabolism of an organism for industrial production of a metabolite.

·       Cancer biology – As the name suggests, it involves understanding the various aspects of cancer and looking for its cure.

·       Neurobiology – It is the study of the nervous system.

·      Developmental biology – This field involves studying how a multicellular organism is formed from a single cell.

·       Botany – Study of plants.

·       Zoology – Study of animals.

·       Ecology – Study of the ecosystem.

All the above fields are trying to understand the mystery called ‘life’. As you may recollect from the introductory texts of your high school biology, life is organized at various levels. We see life in the form an organism. The organism is coordinated system of organs, which are made up of tissues and cells. Cells can be broken down to molecules and atoms. Organisms of the same kind make a species whereas organisms of different kinds make an ecosystem. If you look at the descriptions of all the above fields, you will notice that they ‘look’ at ‘life’ at various levels and in different frames of reference. Botany, Zoology, and Microbiology focus on the organism itself. Ecology and evolutionary biology study groups of organisms. Immunology, neurobiology, cancer biology, and developmental biology are fields which analyze processes within an organism. Cell biology focuses on a single cell, whereas biochemistry, molecular biology, and biophysics deal with molecules within or associated with the cell. Some fields such as bioinformatics, genetic engineering, and structural biology are only tools which help you understand the processes associated with ‘life’. Fields like synthetic biology and systems biology approach the same questions with a completely different perspective.

Although life sciences have been divided into many major and minor disciplines, the nature of research is always interdisciplinary. Let’s take an oversimplified example. Say, you have noticed natural degradation of a xenobiotic compound at a landfill site. The question here is, which microbial agent(s) is responsible for the degradation of the xenobiotic compound? Can this agent be exploited to degrade the same compound at other landfill sites? The first step here is to isolate the microbial agent. This procedure makes use of the principles of microbiology. The techniques of microbiology will lead you to the isolation, identification, and characterization of the microorganism. The next step is to find out the enzyme(s) synthesized by the microorganism, which degrades the xenobiotic compound. Tools and techniques of biochemistry, molecular biology and bioinformatics will help in this investigation. To understand the exact mechanism of the enzyme action, structural biology can be used. The question would be whether this enzyme or the microorganism itself can be used for xenobiotic compound degradation at other sites. The microorganism perhaps needs a specific microhabitat; in which it can express the enzyme of interest. The study of a microhabitat belongs to the field of microbial ecology. Can you rewire the network of genes so that the microorganism can express the enzyme under conditions of your choice? To approach this question, you have to enter the field of synthetic biology. During the whole process, you may need to purify a protein, acquire microscopic images, run enzyme assays, construct mutants, perform PCR, and so on. So, which field does this research question belong to? At a bird’s eye view, the research question belongs to environmental microbiology. However, to answer the research question one needs to use principles and techniques of various other fields. Your PhD may be just about the identification of the gene that encodes the enzyme involved in the degradation of the xenobiotic compound. In this case, you will be spending most of your time with molecular biology techniques. But, you will also gain insights into the field of microbial ecology and the techniques specific to it.

Research questions in the fields of cancer biology, neurobiology, developmental biology, and immunology are way more complicated than the one mentioned above. You entire PhD can be based on understanding the function of a single protein domain, which is likely to be involved in a certain pathway that is related to a specific form of cancer. In this case, you will be using all the principles and techniques of the disciplines that ‘look’ at life at a molecular level. Also, you will study the basics of cancer biology and various other things related to that field. In short, a PhD is all about giving you a thorough understanding of a particular field at all levels. Eventually, when you succeed, it will be a step (albeit, small) towards finding a cure for cancer. Overwhelming, isn’t it? That’s why it is called ‘research’!

Now let’s move to the strategy of determining your own area of interest. There are two ways of doing it. One is ‘textbook-to-research group’ approach and the other is ‘choosing the most interesting research group’ approach. Is there something from our textbook that interests you a lot? Are you fascinated with enzymes? Do you find it interesting to study how neurons function? Are you excited about playing with computer-generated models of biomolecules? Regardless of whether we understand the nature of research, there is always something that we find exciting. Choose any such research area and start reading the latest research literature related to that area. If you cannot choose one, choose three and rank them according to your level of involvement.  Understand the tools and techniques that are used by researchers in that area. Talk to some PhD students working in that area. Attend lectures given by the scientists working in that area. Check if you have sufficient theoretical and practical background to work in that area. If you don’t have enough experience, consider doing a small summer internship or doing your M.Sc. dissertation in that area. After having a lookout, you can start looking for the research groups working in the particular area. Remember, it is an ‘area of interest’ and not a specific research question.

Sometimes, it can happen that you find many fields equally enticing. In this case, think the opposite way. Is there something that you do NOT wish to do? I went through a similar crisis while applying for a PhD. I used to like most disciplines of life sciences and I was confused about which one to choose. However, there were certain things that I strongly disliked. I never enjoyed handling animals for performing experiments. So, the research areas like immunology, infection biology, cancer biology, neurobiology, and developmental biology, which may involve animal handling were not for me. Also, I never found it exciting to sit in front of a computer day in and day out. Thus, I excluded the research areas, which extensively used the tools of bioinformatics and computational biology from my list. Consequently, I was left with fewer research groups that were working in the areas I was comfortable with. I simply chose a research group that was working on something exciting and was hiring PhD students. In short, if you do not know what you like, you should at least know what you do NOT like!

The second approach is to choose the most interesting research group out of the available options. If you neither have something exciting, nor something that you find boring, it can be a bit difficult to choose the research group. In this case, you can simply start looking at the available PhD positions and check if you find something generates curiosity. Have a look at the research group’s homepage. Go through their publications. Try to get an idea of the tools and techniques they are using. Check if your background is suitable for working in that research group. If everything fits well, hit the apply button. This approach can be tedious, time-consuming, and also frustrating. Remember, it is of utmost importance that you have a passion (or at least some level of interest) for working in a particular research area. It is this passion that will help you sustain during in the ups and downs of a PhD life!


I hope this post has helped you to identify your very own area of interest. If you have any further questions, please comment below.  I would love to answer them. If you have any suggestions to improve the contents of this post, please do not hesitate to comment.