Featured Research

from universities, journals, and other organizations

Physicists Find Way To Explore Microscopic Systems Through Holographic Video

Date:
July 30, 2009
Source:
New York University
Summary:
Physicists have developed a technique to record 3-D movies of microscopic systems, such as biological molecules, through holographic video. The work has potential to improve medical diagnostics and drug discovery.

In the microscope, a laser beam illuminates the sample. Light scattered by the sample creates an interference pattern which is magnified and recorded. Then measurements of the particle's position, size, and refractive index are obtained.
Credit: Image courtesy of New York University

Physicists at New York University have developed a technique to record three-dimensional movies of microscopic systems, such as biological molecules, through holographic video. The work, which is reported in Optics Express, has potential to improve medical diagnostics and drug discovery.

Related Articles


The technique, developed in the laboratory of NYU Physics Professor David Grier, is comprised of two components: making and recording the images of microscopic systems and then analyzing these images.

To generate and record images, the researchers created a holographic microscope, which is based on a conventional light microscope. But instead of relying on an incandescent illuminator, which conventional microscopes employ, the holographic microscope uses a collimated laser beam—a beam consisting of a series of parallel rays of light and similar to a laser pointer.

When an object is placed into path of the microscope's beam, the object scatters some of the beam's light into a complex diffraction pattern. The scattered light overlaps with the original beam to create an interference pattern reminiscent of overlapping ripples in a pool of water. The microscope then magnifies the resulting pattern of light and dark and records it with a conventional digital video recorder (DVR). Each snapshot in the resulting video stream is a hologram of the original object. Unlike a conventional photograph, each holographic snapshot stores information about the three-dimensional structure and composition of the object that created the scattered light field.

The recorded holograms appear as a pattern of concentric light and dark rings. This resulting pattern contains a wealth of information about the material that originally scattered the light—where it was and what it was comprised of.

Analyzing the images provided a different set of challenges. To do so, the researchers based their work on a quantitative theory explaining the pattern of light that objects scatter. The theory, Lorenz-Mie theory, maintains that the way light is scattered can reveal the size and composition of the object that is scattering it.

"We use that theory to analyze the hologram of each object in the snapshots of our video recording," explained Grier, who is part of NYU's Center for Soft Matter Research. "Fitting the theory to the hologram of a sphere reveals the three-dimensional position of the sphere's center with remarkable resolution. It allows us to view particles a micrometer in size and with nanometric precision—that is, it captures their traits to within one billionth of a meter."

"That's a tremendous amount of information to obtain about a micrometer-scale object, particularly when you consider that you get all of that information in each snapshot," Grier added. "It exceeds other existing technology in terms of tracking particles and characterizing their make-up—and the holographic microscope can do both simultaneously."

Because the analysis is computationally intensive, the researchers employ the number-crunching power of the graphical processing unit (GPU) used in high-end computer video cards. Originally intended to provide high-resolution video performance for computer games, these cards possess capabilities ideal for the holographic microscope.

The team has already employed the technique for a range of applications, from research in fundamental statistical physics to analyzing the composition of fat droplets in milk.

More broadly, the technique creates a more sophisticated method to aid in medical diagnostics and drug discovery. At its most basic level, research in these areas seeks to understand whether or not certain molecular components, i.e., the building blocks of pharmaceuticals, stick together.

One approach, called a "bead-based assay," creates micrometer-scale beads whose surfaces have active groups that bind to the target molecule. Because of their small size, the challenge for researchers is to determine if these beads actually stick to the target molecules. The way this is traditionally done is to create yet another molecule—or tag—that binds to the target molecule. This tag molecule, time-consuming and costly to produce, is typically identified by making it fluorescent or radioactive.

The holographic imaging technique, with its magnification and recording capabilities, allows researchers to observe molecular-scale binding without a tag, saving both time and money. Requiring just one microscopic bead to detect one type of molecule, holographic video microscopy promises a previously unattainable level of miniaturization for medical diagnostic tests and creates possibilities for running very large numbers of sensitive medical tests in parallel.


Story Source:

The above story is based on materials provided by New York University. Note: Materials may be edited for content and length.


Cite This Page:

New York University. "Physicists Find Way To Explore Microscopic Systems Through Holographic Video." ScienceDaily. ScienceDaily, 30 July 2009. <www.sciencedaily.com/releases/2009/07/090720111450.htm>.
New York University. (2009, July 30). Physicists Find Way To Explore Microscopic Systems Through Holographic Video. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2009/07/090720111450.htm
New York University. "Physicists Find Way To Explore Microscopic Systems Through Holographic Video." ScienceDaily. www.sciencedaily.com/releases/2009/07/090720111450.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Who Will Failed Nuclear Talks Hurt Most?

Who Will Failed Nuclear Talks Hurt Most?

Reuters - Business Video Online (Nov. 25, 2014) With no immediate prospect of sanctions relief for Iran, and no solid progress in negotiations with the West over the country's nuclear programme, Ciara Lee asks why talks have still not produced results and what a resolution would mean for both parties. Video provided by Reuters
Powered by NewsLook.com
Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Reuters - Innovations Video Online (Nov. 25, 2014) A virtual flying enthusiast converts parts of a written-off Airbus aircraft into a working flight simulator in his northern Slovenian home. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins