Principal Investigator

Thorsten Wohland

Prof. Thorsten Wohland

Post-doc.: Stanford University (USA)
Dr. es. sc. (equiv. Ph.D.): Swiss Federel Institute of Technology at Lausanne (EPFL, Switzerland)
Dipl. Phys. (Physics): University of Heidelberg (Germany)

Research Interests

Biophysical Fluorescence

The research in my group is directed towards biophysics with an emphasis on biophysical fluorescence. This highly interdisciplinary domain requires the interaction of chemists, physicists, and biologists. Only a concerted effort of these three groups will allow us to tackle the problems in the life sciences. The close proximity of departments of biology, biochemistry, chemistry, and physics at the National University of Singapore on one side and the research institutes (RIs) on the other side, allows us to develop physical and chemical methods for the study of biological questions on one hand and to apply these methods to the frontier in biology on the other hand. Our interests lie accordingly in the different areas that interact freely to advance this research field.

Construction and development of new optical tools. Optical Spectroscopy is one of the most sensitive tools available in the life sciences. Proteins can be studied not only in ensembles but as well on the single molecule level. Besides using well established methods in our group (e.g. Fluorescence Correlation Spectroscopy, Fluorescence Resonance Energy Transfer), we also plan to develop new spectroscopy and microscopy tools and new mathematical procedures to study proteins on a single molecule level in vitro and in vivo.

Study of selected proteins and protein complexes on a single molecule level and in living cells. In collaboration with the Department of Biological Sciences, the Department of Microbiology and the RIs we will study the properties of selected proteins and peptides to elucidate their function on a molecular level. At the moment we concentrate on either antimicrobial peptides and their interaction with bacterial membranes, or on the study of transmembrane proteins (G-protein coupled receptors, growth factors) and their structure, function and interactions.

One of the most interesting questions in biology is the relationship between the structure and function of proteins. With the fluorescence tools developed in our group we hope to shed some light on this question by in vitro experiments. In a complementary approach we will study the proteins in living cells because proteins are in many cases very sensitive to their environment and only when studied under physiological conditions can we determine their exact function.

email: twohland@nus.edu.sg
Telephone: (+65) 6516 1248
Personal Webpage

Research Fellows

jagadish sankaran

Jagadish Sankaran

Research Fellow: Mechanobiology Institute, Singapore
Ph.D., (Computation and Systems Biology): Singapore-MIT Alliance
B.Tech., (Industrial Biotechnology): Center for Biotechnology, Anna University, Chennai (India)

Research Interests

Understanding the diffusion properties of biofilms using fluorescent techniques.

Bacterial biofilms are communities of bacteria attached to a surface embedded in extracellular polysaccharides. In many cases, bacterial biofilms are found to be resistant to antibiotics. Currently, there are two different theories regarding the reasons for resistance. One of them is the presence of persistor cells which are known to be genetically altered and possess the antibiotic resistance genes. Another school of thought say that the extracellular polysaccharides surrounding the biofilm form a diffusion barrier to these antibiotics. It is plausible that the antibiotic resistance is conferred by a combination of both these mechanisms. The project aims to elucidate the contribution of physical mechanisms in conferring resistance to antobiotic for biofilms. This project is done in collaboration with SCELSE, Singapore Center for Environmental Life Sciences Engineering.

email: dbsjsk@nus.edu.sg

Nirmalya Bag

Kamal Kant Sharma

Research fellow: University of Strasbourg (UDS), Strasbourg, FRANCE; from 10/12 till 03/16
Research fellow: Case Western Reserve University, Cleveland, Ohio, USA; from 05/11 till 09/12
Ph.D., (Biophysics): University of Strasbourg (UDS), Strasbourg, FRANCE
M.Sc., (NanoScience): Amity University (AINT) (India) 
B.Sc., (Life Sciences): Delhi University (India)

Research Interests

Revealing molecular events of the Dengue Virus during its infection process, its effect on the host cell, and its replication mechanisms by using Fluorescence spectroscopy and imaging techniques 

Dengue Virus (DENV) is an enveloped RNA Virus that contains a 11 kb positive sense RNA as its genome and belongs to the family Flaviviridae. Despite its high clinical impact, little is known about the infectious cell entry/exit pathway. Recently, using live cell imaging techniques it has been shown that DENV particles are delivered to pre-existing clathrin-coated pits by diffusion along the cell surface. Consequently, due to membrane fusion with late endosomes, its viral content is released into the cytoplasm of host cell. Although earlier studies provide ample insight into the viral cell entry/exit mechanisms still the associated changes at molecular level within virus and the host cell are missing. I am interested in joining such missing links. To obtain this, different biophysical, bioimaging and biochemical techniques, like single molecule FRET, confocal FCCS, imaging FCS, anisotropy and time-resolved spectroscopy, will be used.

email: dbskks@nus.edu.sg

Cathleen Teh

Cathleen Teh

Research Interests

Dr Cathleen Teh's completed her undergraduate and post-graduate studies in National University of Singapore. Her research interests include generating novel transgenic zebrafish to track physiological function by live imaging and developing zebrafish based strategies to assess nanomaterial function and their potential biomedical application in vivo.

Records of research activities from Google Scholar- Cathleen Teh (updated on 27th April 2018)

Total publications: 35

Total citations: 1950

H-index: 16

I10-index: 22

ResearchGate profile: https://www.researchgate.net/profile/Cathleen_Teh

email: dbstc@nus.edu.sg

Cathleen Teh

Debjit Roy

Ph.D., (Fluorescence Spectroscopy): Indian Institute of Science Education and Reseach Kolkata (IISERK), Kolkata, India
M.Sc., (Chemistry): University of Calcutta, Kolkata, India
B.Sc., (Chemistry): University of Calcutta, Kolkata, India

Research Interests

Investigating organoids using lattice light sheet microscopy – fluorescence correlation spectroscopy imaging techniques.

email: dbsdebj@nus.edu.sg

Anjali Gupta

Anjali Gupta

Ph. D (National University of Singapore)- Membrane Biophysics

BS-MS Dual Degree (Biological Sciences), IISER-Mohali (India)

Research Interests

Understanding the biophysical and structural basis of allosteric activation of Epidermal Growth Factor receptor using FCS and mass spectrometry

Epidermal growth factor receptor (EGFR) signaling is involved in diverse fundamental physiological processes such as cell proliferation and apoptosis. Upregulated tyrosine kinase activity of the EGFR/ErbB family is often implicated in a variety of human cancers. Even after decades of research on this signalling there are still gaps in our understanding of activation mechanism of EGFR at and across membranes. Most of the studies carried out on EGFR are on either extracellular or intracellular region of receptor but it is now speculated that transmembrane and juxtamembrane region of receptor are playing important roles in activation and regulation of EGFR signalling. Secondly, being an integral membrane protein EGFR actively interacts with its surrounding membrane environment but it is not well understood what are these interactions and how they affect the signalling. In order to fill some of the existing gaps in understanding of EGFR signalling in my project I plan to study the biophysical and structural basis of allosteric activation of EGFR signalling using Fluorescence Correlation Spectroscopy (FCS) and mass spectrometry. A combination of these two methods will provide information about lateral interactions crucial for EGFR signalling and allosteric changes taking place in the receptor across the membrane.

email: dbsag@nus.edu.sg

Ph. D students

Sarala

Sarala Neomi Tantirimudalige

B.Sc. (Chemistry-Computational): University of Colombo (Sri Lanka)
M.Sc. (Analytical Chemistry): University of Colombo (Sri Lanka)

Research Interests

Dengue virus is an enveloped positive sense RNA virus from the Flaviviridae family which causes dengue fever and dengue hemorrhagic fever. The spread of dengue is increasing and yet no effective preventive vaccines are currently available. To find a possible way to prevent the virus infection, it is of utmost importance to study the viral infectious pathway and its modes of infection. To do this I utilize Single Particle Tracking (SPT) as a powerful tool which can follow a single viral particle, and decipher its infectious pathway in live cells. I use fluorescence microscopy to study the viral movements on live cell membrane and inside cell cytosol in real-time by using a self-written 3-Dimensional Single Particle Tacking software plug-in which runs on Micromanager 1.4, fully capable of following single particles by moving the piezo stages of the SPIM microscope to bring the particle back into focus each time it moves out of focus in the z-axis. It uses a weak astigmatic lens which changes the Point Spread Function (PSF) of the particle, indicating where in relation to the focus the particle has moved, allowing an on-the-fly feed-back loop to move the sample back into focus. Viral infection can occur using many different receptors and attachment factors and not all routes of entry are yet known for dengue virus and I currently investigate possible involvement of cellular gangliosides as viral receptors or interaction sites during early infection stages. Involvement of viral glycans during early stages of infection and viral conformational changes during infection is also studied using 3D-SPT and 3D-smFRET-SPT (3-dimensional single molecule Förster resonance energy transfer).

email: e0010756@u.nus.edu

Sarala

Sapthaswaran Veerapathiran

M.Sc(Integrated) Biological Sciences : BITS Pilani (Hyderabad Campus), India

Research Interests

Study of development of zebrafish embryo using Light Sheet Imaging - Fluorescence Correlation Spectroscopy.

email: sapthaswaran@u.nus.edu

Sarala

Harikrushnan Balasubramanian

B. Tech. (Biotechnology): SRM University, Chennai, India

Research Interests

Investigation of membrane dynamics and organization of epidermal growth factor receptor (EGFR) by fluorescence methods

email: harikrushnan@u.nus.edu

XinEe

Xin Ee Yong

B. Sc., (Life Sciences - Molecular and Cell Biology): National University of Singapore

Research Interests

Studying broadly neutralizing antibodies against Dengue Virus using biophysical techniques such as time-resolved FRET, FCS and HDXMS. 

email: xinee.yong@u.nus.edu

Tang

Wai Hoh Tang

Currently a PhD student in Department of Statistics and Applied Probability, National University of Singapore

M.Sc. (Quantitative Finance) & B.Sc. (Physics): National University of Singapore

Research Interests

Using convolutional neural networks to analyze sequences of fluorescence spectroscopy images

In recent years, neural networks have received an increased amount of attention in the field of computer vision, especially after the introduction a convolutional neural network (CNN) architecture, called AlexNet, which won the 2012 ImageNet challenge. The state-of-the-art of visual recognition and object detection has dramatically improved and various embellishments of CNNs have been proposed since then. In this study, we aim to leverage on feature extraction capability of CNNs to analyze FCS image stacks. We want to find suitable CNNs that can estimate diffusion coefficients of particles and provide statistical properties of the estimations.  This study is jointly supervised Associate Professor Adrian Roellin, from Department of Statistics and Applied Probability and Professor Thorsten Wohland.

email: tang.waihoh@u.nus.edu

Ashwin Venkata Subba Nelanuthala

M.Sc(Hons.) Physics
BE (Hons.) Mechanical Engineering:  BITS-Pilani (Hyderabad Campus), India

Research Interests

Investigating how morphogen gradients form in zebrafish embryos by the evaluation of Spatial Cross-Correlations on image stacks obtained using light sheet microscopy.

email: ashwinnvs@u.nus.edu

Research Associate

Indira

Indira Kartigayen

M.Sc (Microbiology): University of Madras, India

Research Interests

Developmental study in zebrafish based on dynamics of wnt morphogen by generating transgenic lines with wnt3_mEGFP tagged reporter. Enabling live imaging based developmental studies in zebrafish through transgenesis in terms of molecular based techniques.

email: dbski@nus.edu.sg

  • NUS
  • Biophysical Fluorescence Laboratory