Beauty is in the eye of the microscopist

Scientists have been using microscopes to produce up-close views and gather data about cells and other tiny things for more than 400 years. Many times, however, those images are not just informative, they are beautiful.

actin

Actin network in mouse fibroblast (Image by Dong-Hwee Kim)

Dong-Hwee Kim, a postdoctoral fellow in the Institute for NanoBioTechnology in the Whiting School of Engineering, frequently uses microscopy in his research on cell mechanics, a field he describes as “one of the fastest growing interdisciplinary fields in biology.”

Several of his images have not only yielded abundant quantitative and qualitative data, but they have netted him awards for scientific imaging.

In 2011 he earned an Image of Distinction Award from the Nikon Small World Competition for his photo of a dis-organized perinuclear actin cap stress fibers in a mouse embryonic fibroblast. That same year, he was awarded an Honorable mention from the American Society for Cell Biology 7th Annual Cell Biology film contest for his movie “Hurricane: Cell Cytoplasm Movements”. And in 2013, Kim took second place in the Biophysical Society’s, The Art of Science Image Contest for his dandelion-like representation of the geodesic actin network in a mouse fibroblast.

Kim says his primary focus in collecting these images has always been purely for scientific purposes. “I am trying to better understand how cells recognize the physical properties of the cell environment and respond to them,” he said.

Engineers have developed theories about cell mechanics and about what they expect to happen at the single cell level. But instead of describing the cell’s response with a computational model or other simulation, Kim was determined to capture actual images of live cells reacting to their surroundings.

Perinuclear actin cap stress fibers in a mouse embryonic fibroblast (Image by Dong-Hween Kim)

Perinuclear actin cap stress fibers in a mouse embryonic fibroblast (Image by Dong-Hwee Kim)

“Direct visualization of cell functions has become one of the most effective ways to support scientific findings, since it is the simplest but most powerful way to con-vince others,” he said.

Using various microscopy techniques, Kim has been able to visualize cell components, such as the nucleus or actin filaments, in very detailed ways. “It is always exciting to become the first one to show something that others haven’t seen yet,” he said.

Denis Wirtz, Kim’s advisor, noticed how beautiful the postdoc’s images were and suggested that he enter some of his work into popular imaging contests. Each contest focuses on a different theme, but the bottom line is that the images must be scientifically relevant as well as visually interesting. For example, the image of the geodesic actin network in the mouse embryonic fibroblasts, which were used for both the Nikon and Biophysical Society image contests, “directly visualized the mechanical and spatial coordinates of filamentous actin cytoskeleton in the cell,” said Kim. But the images also happen to be reminiscent of dandelions and fireworks.

Even if making a pretty picture is not the intent of the image, Kim thinks that having an artistic eye is important in science.

“I think artistic images in science should be based on a combination of aesthetic discrimination and scientific significance, which gives them unparalleled power to support scientific findings and persuade others,” Kim said.

The old saying goes, “a picture is worth 1,000 words.” In this case an expertly executed scientific image “can overcome myriad arguments,” Kim added.

Kim said his favorite imaging tool is the “confocal laser scanning microscopy, which allows high resolution images in cell biology, as well as qualitative and quantitative analysis of images.” He emphasizes that he does not use any software enhancements, such as Photoshop, to beautify his images. However, by attempting to create a beautiful image, he has developed several new imaging protocols.

“In challenging myself to create artistic images, it has sometimes led me to design new scientific methodologies that were not conventionally used in the field, and I think these efforts can contribute to the advancement of science,” Kim said.

This article was written by Mary Spiro, science writer for INBT at Johns Hopkins University, and first appeared in the 2013 issue of Nano-Bio Magazine.

 

Johns Hopkins and UVa co-host 2-day imaging workshop

Learn about state-of-the-art imaging methods at the In Vivo Preclinical Imaging: an Introductory Workshop, March 20-21 at Johns Hopkins University’s School of Medicine Turner Auditorium. Co-hosted by Johns Hopkins University, the University of Virginia and the Society of Nuclear Medicine (SNM), this workshop will bring together gifted lecturers to cover the fundamentals of in vivo small animal imaging.

The workshop will cover an incredible breadth of material of interest and value to physicians, scientists (including postdoctoral fellows and graduate students) and scientific laboratory professionals interested in using molecular imaging for in vivo biomedical applications. Individuals with experience in small animal imaging as well as beginners are welcome. Participants learn the fundamentals of various small animal imaging modalities. A limited number of participants will also have the opportunity to register to attend a half-day, hands on workshop held on the afternoon of the second day, March 21. Registration for this unique opportunity is on first-come first-served, so don’t wait to register.

Speakers will address imaging modalities including MRI and MRS, PET, SPECT, optical imaging (bioluminescence & fluorescence imaging/tomography), ultrasound, x-ray CT, photoacoustic imaging and multimodality imaging. Speakers will also examine instrumentation, acquisition and reconstruction, MR/SPECT/PET imaging probes, targets and applications, small animal handling, techniques for imaging infectious disease models and data analysis.

More information about the workshop, including a full agenda of topics, registration and details about transportation and lodging can be found at the workshop website. www.snm.org/pci2012.

 

Hopkins Imaging Initiative to host first annual conference

The Johns Hopkins University Imaging Initiative will host the first annual Imaging Conference, October 6, 2011 at the Turner Auditorium on the medical campus. The conference features afternoon lectures from various Hopkins faculty followed by a research poster session and happy hour. Anyone interested in imaging is welcome to attend.

Speakers include Elliot McVeigh, director of the Department of Biomedical Engineering; Elliot Fishman, MD, director of diagnostic imaging at body CT at Johns Hopkins Hospital; Jerry Prince, the William B. Kouwenhoven Professor of Electrical and Computer Engineering at the Whiting School of Engineering; Xingde Li, associate professor of biomedical engineering and head of the Laboratory of Biophotonics Imaging and Therapy at the Whiting School; Peter van Zijl, professor of radiology at the school of medicine and director of the F.M. Kirby Research Center for Functional Brain Imaging; and several others to be announced.

Abstracts will be accepted until Sept 6 and conference registration will be accepted until October 1. For complete information about this event and to register, go to http://imaging.jhu.edu/conferences/imaging-conference-2011

 

 

 

 

Johns Hopkins Integrated Imaging Center focuses on data

Shyenne Yang positions Drosophila embryos for fluorescence imaging. Photo by Marty Katz/baltimorephotographer.com

Heavy, black curtains and dimmed lights shroud the core of the Johns Hopkins Integrated Imaging Center (IIC). Yet researchers who peer through the advanced microscopes cloaked by these dark draperies view experimental samples more clearly than ever thanks to a combination of the high-tech equipment and the creative expertise offered by the center’s seven-member staff.

When describing Johns Hopkins University’s showpiece microscopy facility, it’s easy to rattle off a laundry list of available equipment and laboratory space able to prepare samples with nearly any contrasting agent found in the literature. The Homewood-based center contains devices that can image a sample in virtually any manner in 2-D, 3-D and even 4-D. IIC’s 3,500 square-foot facility comprising space in Dunning, Jenkins, and Olin Halls, boasts more than $7.5 million worth of state- of-the-art imaging equipment, including a Zeiss laser scanning microscope (LSM) 510 VIS confocal with a Confocor 3 fluorescence correlation spectroscopy (FCS) module—one of only a very few such uniquely configured laser scanning microscopes in the United States.

Director J. Michael McCaffery, a research professor in the Department of Biology at the Krieger School of Arts and Sciences, said the Hopkins community is thrilled to have access to such a versatile microscope with fluorescence correlation spectroscopy that is capable of cross-correlation analysis, with confocal imaging and a fully enclosed environmental system for live imaging. Researchers affiliated with Johns Hopkins Institute for NanoBioTechnology (INBT), the Johns Hopkins Physical Sciences Oncology Center and Center of Cancer Nanotechnology Excellence are also glad to have access to IIC’s menu of facilities.

“Fluorescence correlation spectroscopy allows for high-resolution spatial and temporal analysis of single biomolecules with respect to diffusion, binding, as well as enzymatic reactions in vitro and in vivo,” McCaffery said. In other words, you can see and measure a lot of really tiny stuff with it, something INBT affiliated researchers working at micron/nanometer resolutions are finding incredibly useful.

The center features multiple suites devoted to specific microscopy/imaging functions, as well as facilities for all manner of sample preparation. All these advanced tools help scientists and engineers characterize nanomaterials; and image cells, sub-cellular organelles, and biomolecules/ proteins at very small dimensions. But none of this fancy equipment would be of much use to researchers without the expertise of McCaffery and the IIC staff. McCaffery brings years of experience and a background in cell biology and microbiology. The center’s associate director, William Wilson, an associate research professor in the Department of Materials Science and Engineering at the Whiting School of Engineering, describes himself as a “chemist, turned physicist, who became an electrical engineer, who is now a materials scientist.”

Staff scientist Kenneth J.T. Livi, director of the IIC’s High-Resolution Analytical Electron Microbeam Facility located in Olin Hall, offers his unique perspective on earth and planetary sciences. Researchers can also consult with microscopy specialist/ trained biologist and FACS supervisor Erin Pryce, the FACS manager Yorke Zhang, computer/IT specialist Marcus Sanchez, and research assistants Leah Kim and Adrian Cotarelo, who both are currently earning their bachelor degrees in biology at Johns Hopkins.

From left, IIC director Michael McCaffery, FACS supervisor Erin Pryce, and associate director William Wilson with the BD FACSVantage SE. Photo by Mary Spiro

“Sometimes young researchers haven’t contemplated all the possibilities of how to use and apply an instrument; and don’t realize there are many different ways to utilize familiar tools in order to obtain new, in some cases better, information,” McCaffery said. “Our desire is always to approach a problem from many disparate perspectives to generate convergent data that corroborates each particular assay. Hopefully, results from each individual assay, allows the scientist to arrive at a convergent perspective that yields confidence in the results and conclusions.”

One of the easiest ways to obtain different microscopy data and improve corroboration among assays is simply to change the contrast mechanism.

“The most common contrast mechanisms used to image something are optical contrast (transparent versus opaque), polarization, and fluorescence,” said Wilson. “But there are many different ways you can manipulate how light interacts with the specimen and what you detect out of an objective.”

For example, ultrafast laser sources have made nonlinear optical forms of contrast an exciting new tool. Techniques like two-photon excited fluorescence and second harmonic generation (both available in the IIC) produce excellent spectral and structural information about samples because a smaller effective photon volume is excited. Wilson explained it like this: “Imagine turning your stereo all the way up and hearing the sound distorted. That distortion is created by the higher order acoustic harmonics from your stereo. The same happens with intense laser light resulting in new “colors” being generated from the object irradiated. The cool thing is that the different non-linear processes are often sensitive to different physical proper- ties or structural features, offering complementary information about your sample.”

In some cases, getting more detailed information simply requires looking at the right color range. The two-photon fluorescence and second harmonic signals appear at different wavelengths. If you excite a sample with enough energy to generate third order harmonics, that signal is detected at an even bluer wavelength, Wilson said. “With third harmonic generation, you only get signals from the interface of structures with no interference from anything else. This means you can simultaneously image fluorescence, polar order, and interface dynamics just by popping in a few filters and beam splitters,” he said.

“Over the past ten or so years, physicists and engineers focused on advanced microscopy, have produced better and more advanced laser and optical technologies, generating techniques that many researchers in the biological and biomedical sciences might not know exist,” Wilson said. “There also are a lot of applied physicists who are developing and using these new technologies who don’t know what an interesting sample is. We hope to help bridge this gap, becoming a place where these collaborative synergies can flourish.”

Sample preparation is another area where the center can help researchers. “Cell fractionation, for example, which is the breaking down of whole cells and separating them into their individual components, when combined with biochemical techniques and microscopy, can often allow researchers to pose more precise questions and to better analyze a biological problem,” McCaffery said.

“It is common for someone to come in and want to use a particular instrument or technique they read about in a paper,” McCaffery said. When that happens, McCaffery and Wilson are likely to give researchers “homework.”

“It’s important to remember that the goal is not to make a pretty picture,” Wilson said. “The goal is to answer a question, so sometimes we have to ask them, ‘What is your research question?’” An enviable set of microscopy tools combined with a team that brings years of training and experience from a variety of disciplines sets Johns Hopkins Integrated Imaging Center apart from the microscope on the individual researcher’s lab bench, as well as from facilities nationwide. Wherever possible, McCaffery said, IIC staff tries to be engaged in all of the research that is carried out in the center. “Simply, our involvement leads to better results and better science,” McCaffery added.

Researchers confirm this successful combination.

“The facilities at the IIC have allowed us to obtain critical information about the internal structure of our peptide nanomaterials that would have remained unknown without careful electron and fluorescence microscopy,” said J.D. Tovar, assistant professor of Chemistry. “Equally important, the scientific IIC staff members were vital participants making sure collaborative experiments were done meaningfully and students were trained competently. Our collaboration with Dr. Wilson has given some nice insights and at the same time has posed many more questions for future research.”

Praise like that for the IIC is always nice to hear, staff members say, but they emphasize that the services and tools they provide are just part of the job. “Part of being a scientist is learning not only how to gather information from a wide variety of tools but also understanding how to pose clear questions that lead to the right tools, in a nutshell, how to not waste time. If we can help you do that, then we have achieved our goal,” Wilson said.
This story originally appeared in Johns Hopkins Nano-Bio Magazine.

To read more about IIC’s facilities and services, go here.

Story by Mary Spiro

Photos by Mary Spiro and Marty Katz