Featured Research

from universities, journals, and other organizations

Building a biochemistry lab on a chip

Date:
February 12, 2013
Source:
University of Illinois College of Engineering
Summary:
Miniaturized laboratory-on-chip systems promise rapid, sensitive, and multiplexed detection of biological samples for medical diagnostics, drug discovery, and high-throughput screening. Using micro-fabrication techniques and incorporating a unique design of transistor-based heating, researchers are further advancing the use of silicon transistor and electronics into chemistry and biology for point-of-care diagnostics.

ÿCross-section of device with a droplet. The left side shows an unheated droplet with the DNA FRET construct in the double-stranded form. The right side shows a heated droplet where the FRET construct has denatured, resulting in an increase in fluorescence.
Credit: Image courtesy of University of Illinois College of Engineering

Miniaturized laboratory-on-chip systems promise rapid, sensitive, and multiplexed detection of biological samples for medical diagnostics, drug discovery, and high-throughput screening. Using micro-fabrication techniques and incorporating a unique design of transistor-based heating, researchers at the University of Illinois at Urbana-Champaign are further advancing the use of silicon transistor and electronics into chemistry and biology for point-of-care diagnostics.

Cross-section of device with a droplet. The left side shows an unheated droplet with the DNA FRET construct in the double-stranded form. The right side shows a heated droplet where the FRET construct has denatured, resulting in an increase in fluorescence.

Lab-on-a-chip technologies are attractive as they require fewer reagents, have lower detection limits, allow for parallel analyses, and can have a smaller footprint.

"Integration of various laboratory functions onto microchips has been intensely studied for many years," explained Rashid Bashir, an Abel Bliss Professor of electrical and computer engineering and of bioengineering at Illinois. "Further advances of these technologies require the ability to integrate additional elements, such as the miniaturized heating element, and the ability to integrate heating elements in a massively parallel format compatible with silicon technology.

"In this work, we demonstrated that we can heat nanoliter volume droplets, individually and in an array, using VLSI silicon based devices, up to temperatures that make it interesting to do various biochemical reactions within these droplets."

"Our method positions droplets on an array of individual silicon microwave heaters on chip to precisely control the temperature of droplets-in-air, allowing us to perform biochemical reactions, including DNA melting and detection of single base mismatches," said Eric Salm, first author of the paper, "Ultralocalized thermal reactions in subnanoliter droplets-in-air," published in the Proceedings of the National Academy of Science (PNAS) on February 12.

According to Salm, approaches to perform localized heating of these individual subnanoliter droplets can allow for new applications that require parallel, time-, and space multiplex reactions on a single integrated circuit. Within miniaturized laboratory-on-chips, static and dynamic droplets of fluids in different immiscible media have been used as individual vessels to perform biochemical reactions and confine the products.

"This technology makes it possible to do cell lysing and nucleic acid amplification reactions within these individual droplets -- the droplets are the reaction vessels or cuvettes that can be individually heated," Salm added.

"We also demonstrate that ssDNA probe molecules can be placed on heaters in solution, dried, and then rehydrated by ssDNA target molecules in droplets for hybridization and detection," said Bashir, who is director of the Micro and Nanotechnology Laboratory at Illinois. "This platform enables many applications in droplets including hybridization of low copy number DNA molecules, lysing of single cells, interrogation of ligand-receptor interactions, and rapid temperature cycling for amplification of DNA molecules.

"Notably," Bashir added, "our miniaturized heater could also function as dual heater/sensor elements, as these silicon-on-insulator nanowire or nanoribbon structures have been used to detect DNA, proteins, pH, and pyrophosphates.

By using microfabrication techniques and incorporating the unique design of transistor-based heating with individual reaction volumes, 'laboratory-on-a-chip' technologies can be scaled down to 'laboratory-on-a-transistor' technologies as sensor/heater hybrids that could be used for point-of-care diagnostics."

In addition to Salm and Bashir, co-authors of the study included Carlos Duarte Guevara, Piyush Dak, Brian Ross Dorvel, and Bobby Reddy, Jr. at the University of Illinois; and Muhammad Ashraf Alam, Birck Nanotechnology Center and the School of Electrical and Computer Engineering at Purdue University.


Story Source:

The above story is based on materials provided by University of Illinois College of Engineering. Note: Materials may be edited for content and length.


Journal Reference:

  1. E. Salm, C. D. Guevara, P. Dak, B. R. Dorvel, B. Reddy, M. A. Alam, R. Bashir. Ultralocalized thermal reactions in subnanoliter droplets-in-air. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1219639110

Cite This Page:

University of Illinois College of Engineering. "Building a biochemistry lab on a chip." ScienceDaily. ScienceDaily, 12 February 2013. <www.sciencedaily.com/releases/2013/02/130212132007.htm>.
University of Illinois College of Engineering. (2013, February 12). Building a biochemistry lab on a chip. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/02/130212132007.htm
University of Illinois College of Engineering. "Building a biochemistry lab on a chip." ScienceDaily. www.sciencedaily.com/releases/2013/02/130212132007.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) — TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) — Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) — When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) — 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
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:
from the past week

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