Featured Research

from universities, journals, and other organizations

Faster CARS, less damage: Chemical microscopy shows potential for cell diagnostics

Date:
November 1, 2010
Source:
National Institute of Standards and Technology (NIST)
Summary:
Recent research may breathe new life into the use of a powerful -- but tricky -- diagnostic technique for cell biology. A new paper demonstrates that with improved hardware and better signal processing, a powerful form of molecular vibration spectroscopy can quickly deliver detailed molecular maps of the contents of cells without damaging them.

B-CARS chemical imaging: Test cells from a mouse as seen in an optical microscope image (left), and using B-CARS (right). The CARS image detects specific molecules to highlight the cell nucleus (green) and intracellular fluid (blue). Images show an area approximately 40 micrometers across. B-CARS image represents approx. 17,000 individual spectra.
Credit: NIST

A paper by researchers at the National Institute of Standards and Technology (NIST) may breathe new life into the use of a powerful -- but tricky -- diagnostic technique for cell biology. The paper, appearing in the Biophysical Journal, demonstrates that with improved hardware and better signal processing, a powerful form of molecular vibration spectroscopy can quickly deliver detailed molecular maps of the contents of cells without damaging them. Earlier studies have suggested that to be useful, the technique would need power levels too high for cells.

Related Articles


The technique, "B-CARS" (short for "broadband coherent anti-Stokes Raman scattering"), is one of several variations on Raman spectroscopy, which measures the frequencies associated with different modes of vibration of atoms and their bonds in a molecule. The exact mix of these frequencies is an extremely discriminating "fingerprint" for any particular molecule, so Raman spectroscopy has been used as a chemical microscope, able to detail the structure of complex objects by mapping the chemical composition at each point in a three-dimensional space.

In the biosciences, according to NIST chemist Marcus Cicerone, Raman spectroscopy has been used to detect microscopic cellular components such as mitochondria, detect how stem cells differentiate into new forms and distinguish between subtly different cell and tissue types. It can, for example, detect minor differences between various precancerous and cancerous cells, potentially providing valuable medical diagnostic information. Even better, it does this without the need to add fluorescent dyes or other chemical tags to identify specific proteins.

The catch, says Cicerone, is speed. The usual method, spontaneous Raman scattering takes a long time to gather enough data to generate a single spectrum -- as much as seven minutes for fine detail -- and that's for each point in the image. "Seven minutes or even five seconds per spectrum is not feasible when we need a million spectra for an image," he observes. CARS, which uses a pair of lasers to pump up the vibrational states and increase signal, is part of the answer. The current breakthroughs for a broadband CARS instrument developed at NIST since 2004, says Cicerone, gets the same information in 50 milliseconds per pixel.

The new catch is power. Recent papers have argued that to get the necessary data, the lasers used in CARS must run at power levels above the damage threshold for living cells, making the technique nearly useless for clinical purposes. Not quite, according to the NIST team. Their paper describes a combination of improved hardware to gather spectra over a very broad range of wavelengths, and a clever mathematical technique that effectively amplifies the useable signal by examining a portion of signal normally ignored as background interference. The result, says Cicerone, pushes their minimum power level below the damage threshold while retaining the speed of CARS. "We have all the information that you have in a Raman spectrum but we get it 5 to 100 times faster," he says, adding that some obvious modifications should push that higher, opening the door to more widespread use of vibrational spectroscopy in both biology and clinical diagnosis.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. S.H. Parekh, Y.J. Lee, K.A. Aamer and M.T. Cicerone. Label-free cellular imaging by broadband coherent anti-Stokes Raman scattering microscopy. Biophysical Journal, 2010; 99

Cite This Page:

National Institute of Standards and Technology (NIST). "Faster CARS, less damage: Chemical microscopy shows potential for cell diagnostics." ScienceDaily. ScienceDaily, 1 November 2010. <www.sciencedaily.com/releases/2010/10/101014121156.htm>.
National Institute of Standards and Technology (NIST). (2010, November 1). Faster CARS, less damage: Chemical microscopy shows potential for cell diagnostics. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2010/10/101014121156.htm
National Institute of Standards and Technology (NIST). "Faster CARS, less damage: Chemical microscopy shows potential for cell diagnostics." ScienceDaily. www.sciencedaily.com/releases/2010/10/101014121156.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher 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


Health & Medicine

Mind & Brain

Living & Well

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