Dynamics Imaging of Biomolecular Assemblies


Single cells are the building blocks for all biological systems; yet they are inherently complex with intricate networks of dynamic biomolecular assemblies made up of proteins, coenzymes, ligands, DNA, RNA and lipids. In addition, these molecular assemblies are dynamically changing their sizes, conformations and intermolecular interactions in response to specific chemical, environmental or biological cues. In Heikal laboratory, we are using fluorescence microscopy (confocal, two-photon, TIRF, and wide-field) and spectroscopy (time-resolved fluorescence, time-resolved anisotropy, FLIM, and FCS) to investigate molecular and cellular biophysics. These noninvasive and quantitative approaches complement traditional biochemical techniques on purified biomolecules from cell lysates.

Our interdisciplinary research interests are focused on understanding the molecular underpinning of cellular processes such as energy metabolism in living cells, mitochondrial dysfunction, biomimetic membranes, and immunoglobulin E receptor signaling. We are also interested in studying protein & molecular dynamics, protein-protein interactions, macromolecular crowding, and spectroscopy. In addition, we are developing fluorescence-based micro-spectroscopic tools, image processing algorithm and modeling.

Students in Heikal laboratory (both undergraduates and graduates) are trained on a number of analytical, biophysical, and biochemical methods that include cell culture, model membrane assemblies, molecular dynamics, optical microscopy and ultrafast laser spectroscopy. Different aspects of scientific research (e.g., experimental design, data and image analysis, critical thinking, scientific writing, communication and teamwork skills) are also emphasized. The students in Heikal laboratory also gain an appreciation of interdisciplinary research at the interface of traditional disciplines of chemistry, biochemistry, biology, physics, and mathematics.






Anh Cong, Rafaela M. L. Pimenta, Hong Bok Lee, Venkatram Mereddy, Jon Holy, Ahmed A. Heikal. "Two-Photon Fluorescence Lifetime Imaging of Intrinsic NAD(P)H in Three-Dimensional Tumor Models". Cytometry (Part A), 2018. DOI: 10.1002-cyto.a.23632.


Hong Bok Lee, Anh Cong, Hannah Leopold, Megan Currie, Arnold J. Boersma, Erin D. Sheets,  and Ahmed A. Heikal. "Rotational and Translational Diffusion of Size-Dependent Fluorescent Probes in Homogeneous and Heterogeneous Environments". Phys. Chem. Chem. Phys., 2018, 20, 24045 – 24057. DOI: 10.1039/c8cp03873b.


Congratulation to Rowna Simonet for her Outstanding Poster Presentation at the Summer Undergraduate Research Program (SURP) Symposium (August 03, 2018).


Ahmed Heikal was an invited speaker at the upcoming SPIE 2018 (Session: Optical Engineering and Applications), which will be held in San Diego, CA (August 19-23, 2018).


Congratulations to Hong Bok Lee for successfully defending his M.S. thesis (May 27, 2018). Hong Bok will attend the Graduate Ph.D. Chemistry Program at the University of Iowa.


Congratulation to Rowna Simonet for her POLYED Award for Achievement in Organic Chemistry (Spring-2018).

Congratulations to Ryan Leighton, the reciepient of Honors from both Chemistry & Biochemistry and Physics, the Physics and Astronomy Research Award, the Lake Superior Section of the ACS Award, and FB Moore Award (Spring-2018).


Congratulations to Abaynhe Worku for his UROP award for the Fall-2018.


Ahmed Heikal was nominated by students for the "Outstanding Academic Advisor Award" forthe academic year of 2017-18.


Congratulations to Shane Wilson for successfully defending his M.S. thesis (August 23, 2017).


Congratulations to Hannah Leopold and Jacub Schwarz for successfully defending their M.S. thesis (August 10, 2017).


Congratulations to Megan Currie for successfully defending her M.S. thesis (May 9, 2017).


On Thursday, October 5th (2017), Ahmed A. Heikal was an invited speaker at the Biophysical Seminar Series at the School of Physics and Astronomy, University of Minnesota, Twin Cities.


Jacob Schwarz, Ryan Leighton, Hannah J. Leopold, Megan Currie, Arnold J. Boersma, Erin D. Sheets, and Ahmed A. Heikal. 2017.“Kinetics model for the wavelength-dependence of excited-state dynamics of hetero-FRET sensors.”  Proc. SPIE 10380-28, Ultrafast Nonlinear Imaging and Spectroscopy III(Submitted, Invited).


Hannah Leopold, Megan Currie, Jacob Schwarz, Erin D. Sheets, and Ahmed A. Heikal. "Molecular spectroscopy and dynamics of novel FRET Sensors in crowded environments". SPIE Optical Engineering and Applications, Ultrafast Nonlinear Imaging and Spectroscopy IV, San Diego, CA, August 6 – 10, 2017, “Invited Talk”.


Megan Currie, Hannah Leopold, Jacob Schwarz, Arnold J. Boersma, Erin D. Sheets, and Ahmed A. Heikal. 2017. "Fluorescence Dynamics of a FRET Probe Designed for Crowding Studies". The Journal of Physical Chemistry (B), 121 (23), 5688-5698. DOI: 10.1021/acs.jpcb.7b01306.


Ahmed Heikal was nominated by students for the "Outstanding Faculty Award" for the academic year of 2016-17.


Erin D. Sheets and Ahmed A. Heikal were awarded the UMD Chancellor's Faculty Small Grant (2016-2017) to investigate the effects of macromolecular crowding on protein folding, biochemical reactions, and transport/diffusion.


Spencer Gardeen, Joseph L. Johnson, and Ahmed A. Heikal. "Fluorescence Fluctuation Analysis of BACE1-GFP Fusion Protein in Cultured HEK293 Cells". Proce. SPIE 9956, Ultrafast Nonlinear Imaging and Spectroscopy IV, 99560K (October 3, 2016), doi: 10.1117/12/2237183.


Congratulatins to Tylor Franklin and Robert Kajer, who have been awarded Undergraduate Research Opportunity Program (UROP) Awards to continue their undergraduate research in Heikal Lab during the Spring-2017.


Ahmed A. Heikal is the recipient of the "Outstanding Academic Adviser Award" for 2015 - 2016 by UMD Student Awards Program.

Ahmed A. Heikal will be presenting an invited talk at the upcoming meeting of the Internationall Soceity of Optical Engineering, SPIE, Ultrafast Nonlinear Imaging and Spectroscopy IV (San Diego, CA, August 30, 2016).

Ahmed Heikal wrote for the "Local View" on "A Respectful Goodbye to a Beloved Elder" in the Duluth News Tribune (March 12, 2016).

Ahmed A. Heikal, collaborators (Dr. Joseph L. Johnson and Dr. Erin D. Sheets), and our students (Megan Currie, Spencer Gardeen, Brenden Berry, Taylor Ward) presented two conference papers at the 60th Annual Biophysical Soceity Meeting (Los Angeles, CA, February 27 - March 2, 2016) and the 251st National ACS Meeting (San Diego, CA, March 13-17, 2016).

Ahmed A. Heikal. 2015. "Understanding Macromolecular Crowding is Critical for Quantitative Cell Biology". SPIE Newsroom, Biomedical Optics & Medical Imaging. DOI: 10.1117/2.1201510.006182, December 11, 2015.

Ahmed Heikal and his collaborators have just pulished the following paper: "Megan Currie, Chang Thao, Randi Timerman, Robb Welty, Brenden Berry, Erin D. Sheets, and Ahmed A. Heikal. 2015. Multiscale diffusion of a molecular probe in a crowded environment: a concept. Proc. SPIE 9584, Ultrafast Nonlinear Imaging and Spectroscopy III, 95840E (August 31, 2015), doi:10.1117/12.2188746."

Ahmed A. Heikal wrote for "Local View" on Mentoring in Higher Education in the Duluth News Tribune (October 8, 2015).

Ahmed A. Heikal was an invited speaker at the Ultrafast Imaging and Spectroscopy conference in the 2015 SPIE Optics and Photonics, San Diego, CA, August 9 - 13, 2015.

Ahmed Heikal co-authored the following peer-reviewed paper: Zhihua Xu, Feng Gao, Elena Makarova, Ahmed A. Heikal, and Victor Nemykin. 2015. "Energy Transfer from Colloidal Quantum Dots to Near Infrared Absorbing Tetraazaporphyrins for Enhanced Light Harvesting", The Journal of Physical Chemistry (C); 119(18): 9754 - 9761 (DOI: 10.1021/acs.jpcc.5b01603).

Ahmed Heikal has participated in the "70th International Symposium on Molecular Spectroscopy", June 22 - 26, 2015, at the University of Illinois at Urbana-Champaign.

Dhanushka Wickramasinghe, Randi Timerman, Jillian Bartusek, and Ahmed A. Heikal. “Partitioning and Diffusion Dynamics of Fluorescently Labeled FTY720 in Resting Epithelial Cells”. InAdvanced Time-Correlated Single-Photon Counting Applications”, Wolfgang Becker (Editor), Springer Series in Chemical Physics 111, Springer (ISBN: 978-3-319-14928-8, DOI: 10.1007/978-3-319-14929-5), Chapter 10, pp 339 - 355 (May 2015).

Ahmed Heikal has provided guidance/mentoring to a team of tenth graders from Proctor High School, who was named the winner of Conrad Spirit of Innovation at the NASA’s Space Kennedy Center in April 2015. The team (Alyssa Hagemeyer, Ben Nicolson, Daniel Roach, Jonny Gales, and Zach Coughlin), “Students Striving for Eco Friendly Engineering (SSEFE), was one of 75 teams entered the Energy and Environment category of the Conrad Spirit of Innovation competition last fall. It is worth noting that Proctor High School was the only public school present at the competition along with teams from Africa, Australia and US Science and Math Schools in the Energy and Environment category.

Spencer Gardeen, Joseph L. Johnson, and Ahmed A. Heikal. "Fluorescence microspectroscopy assessment of the in vitro dimerization of BACE1-GFP fusion protein in cultured cells", The 249th American Chemical Society Meeting, Symposium: Current Topics in Biological Chemistry, Division of Biological Chemistry, Denever, CO, March 22 - 26, 2015.

Rochelle Warner, Tyler Floden, Ahmed A. Heikal, and Erin Sheets. "Molecular and Mechanical Manipulation of Membrane Domains in Planar Supported Bilayers". The 59th Biophysical Society Meeting, Baltimore, MD, February 7 - 11, 2015.

Ahmed A. Heikal was an invited spkeaker at the Department of Chemistry, St. Olaf College, on March 5th, 2015.

Ahmed A. Heikal served as the Acting Assistant Department Head for the UMD Department of Chemistry & Biochemistry during the Fall semester of 2014-15.