Nanobiotechnology Center (NBTC)
The contact angle goniometer measures the surface properties of a liquid. An automatic dispensing system releases a pre-set amount of liquid onto the base. As soon as the substance makes contact, a camera operating at 100 frames per second begins taking photographs. The goniometer is designed to handle pendant, inverted pendant, sessile, and captive bubble drops. Using advanced software called DROPimage, the device makes calculations about surface tension, interfacial tension, contact angle, surface energies of solids, drop dimensions, volume and surface area, as well as surface dilational elasticity and viscosity. The goniometer is also used to study a material by applying it to the base of the device and seeing how a liquid reacts with the material.
Yifan Cheng, a postdoc in the lab of Carmen Moraru, Food Science, used the goniometer to measure the contact angles in various probe liquids of several materials, such as food packaging and bacteria repellant nanostructured alumina surfaces. Her findings enabled the Moraru lab to identify and engineer material surfaces with improved bacteria-repelling properties for food and biomedical applications.
The Zetasizer (Malvern Nano ZS) characterizes nanomaterials in a solution. It uses dynamic light scattering (DLS) to determine a materials particle charge, size, and molecular weight. Materials from 0.6 to 6,000 nanometers can be measured with an electrokinetic potential analysis from -150 to +150 megavolts. A size measurement can be taken with a sample from 12 to 500 microliters. An electrokinetic potential measurement requires a one-milliliter sample.
Kai Ma, a postdoc in the lab of Ulrich Wiesner, Materials Science and Engineering, used the Zetasizer during the development of Cornell dots, ultra-small fluorescent silica nanoparticles used for cancer diagnostics and therapeutic applications. Kai Ma used the device to measure particle size distribution and zeta-potential. By monitoring these physical properties, the lab was able to efficiently optimize the surface modification reactions and develop Cornell dots for clinical applications.
The ellipsometer uses a nondestructive optical method to determine film thickness and optical properties. It measures thin films and almost any material deposited on a substrate. This might include thin metal films, oxides, organic coatings, or biological molecule layers such as DNA. While ellipsometry was originally a technique for macroanalysis, this device combines original technology with polarization contrast microscopy to give it the capacity to perform microanalysis.
The FT-IR (Infrared) is a laser-based measuring device that uses chemical analytical techniques to detect the vibration characteristics of chemical functional groups in a sample. The infrared light on the device interacts with a sample, causing chemical bonds to stretch, contract, and bend. The sample adsorbs infrared radiation in specific wavenumber ranges that can be used for molecular identification. The FT-IR is an excellent device for a researcher who has two materials that look exactly the same. It provides a fingerprint of each material, which can then be analyzed to find its defining characteristics.
The freeze drier dehydrates biological samples, hydrogels, and nanoparticles that are sensitive to high temperatures. The device is nondestructive and convenient, with 10 port drying chambers. Freeze drying is an important technique for the preservation of biological materials.
3D Bio, a start up company founded by Lawrence A. Bonassar, Meinig School of Biomedical Engineering/Sibley School of Mechanical and Aerospace Engineering, and Hod Lipson, Columbia University, is creating real human ears by 3D printing with living cells. The freeze drier is an indispensable piece of equipment to their team.
The NanoSight (Malvern NS300) uses the technology of nanoparticle tracking analysis (NTA) to characterize nanoparticles from 30 to 800 nanometers in liquid suspension. Each particle is individually and simultaneously analyzed by direct observation and measurement of diffusion events. A laser beam is passed through the sample chamber, and the particles in suspension scatter light so they can be easily visualized by the 20x magnification microscope and camera. The camera can take 30 frames per second and captures a video file of the particles. This particle-by-particle methodology produces high-resolution results for particle size distribution and concentration. Both particle size and concentration are measured, while a fluorescence mode provides differentiation of labeled or naturally fluorescing particles.
Monet Roberts, a PhD student in Matthew Paszek’s lab, Smith School of Chemical and Biomolecular Engineering, used the NanoSight to visualize microvesicles shed from cell lines in breast cancer. Using the device, she was able to calculate the hydrodynamic diameter of the particles to output their size distribution and concentration. Because the microvesicles are shed in a range of sizes, the NanoSight’s ability to handle polydisperse samples was essential to the research.
The TIRF microscope, total internal reflection fluorescence, allows a microscopic specimen, usually less than 200 nanometers, to be observed. A laser illuminates the sample at incident angles greater than the critical angle, which results in an evanescent wave that illuminates the sample by exciting single molecules. Because the specimen is not excited beyond the evanescent wave, the imaging system produces fluorescent images at an extremely high quality.
The microscope is equipped with a top-of-the-line camera, taking over 50 frames per second. The device is used by researchers to photograph microscopic objects like single molecules or events such as calcium moving through a cell. Images produced from this device are appropriate for publication.
The NBTC offers minicourses to all users, including those at Cornell, other academic institutions, government agencies, and industry. The courses teach new skills to researchers who need training beyond the primary scope of their field. The courses are intensive, and allow users to develop practical lab skills in new areas.
The center offers three mini courses. Mammalian cell culture minicourse covers the practical techniques associated with initiation and propagation of cell cultures, cell viability assessment, and cryogenic storage of cells. Microfluidics covers techniques used in microfluidic device fabrication. Surface Modification teaches techniques for modifying and characterizing surfaces. Classes are taught in groups of five or fewer and on a first-come first-serve basis.
The Nanobiotechnology Center (NBTC) is a core facility at Cornell University that helps scientists learn how cells communicate with their environment at the molecular level. The center fosters a close collaboration between life scientists, physical scientists, and engineers, bringing together researchers from Cornell, government agencies, industry, and other institutions. The facilities’ equipment and expertise are highly specialized, with devices that are uncommon in laboratories. With around 300 active users at any one time, a variety of projects are happening—from 3D printing with human cells, to imaging molecular events, to the fabrication of Cornell C Dots.
The expertise of the NBTC staff is available to users who need training, support, or advice. “The NBTC provides an organized framework to contribute to all sorts of research ideas. We are one of the few places in the country that supports nano and microfabrication within the biological sciences,” says Michael Shuler, Meinig School of Biomedical Engineering/Smith School of Chemical and Biomolecular Engineering—and director of the NBTC. “The center has acted as a catalyst and focal area in bringing biologists and physical scientists together to solve biological problems through their collaboration of expertise.”