We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App




Portable Device to Quickly Detect Bacterial Pathogens Using New Optical Signature

By LabMedica International staff writers
Posted on 28 Aug 2023
Print article
Image: Dynabeads (grey spheres) interacting with Salmonella bacterium (in green) (Photo courtesy of MIT)
Image: Dynabeads (grey spheres) interacting with Salmonella bacterium (in green) (Photo courtesy of MIT)

Receiving results from a blood test or other diagnostic assessments often involves a waiting period of one to seven days, depending on the specific test's target. This time lag can be primarily attributed to the laborious steps in sample processing and analysis. The quantities of diseased cells or pathogens in fluid samples are so minute that they require cultivation in controlled settings to increase their numbers. Subsequently, these cultures are stained and examined under a microscope. This comprehensive procedure extends over several days to yield a conclusive positive or negative outcome. Now, researchers have identified a new optical signature in a commonly used class of magnetic beads, known as Dynabeads. This discovery holds the potential to speed up the detection of contaminants in various diagnostic tests, such as identifying traces of the foodborne pathogen Salmonella.

Dynabeads, microscopic magnetic beads, are capable of being coated with antibodies that attach to specific target molecules, like pathogens. Typically, Dynabeads are integrated into solutions to capture desired molecules, but further time-consuming steps are essential to confirm their presence and attachment to the beads. A team of scientists at Massachusetts Institute of Technology (MIT, Cambridge, MA, USA) have leveraged optics, specifically Raman spectroscopy, to confirm the presence of Dynabead-bound pathogens. Raman spectroscopy is an optical technique for identifying specific molecules through the unique way in which a molecule scatters light, referred to as their "Raman signature." The researchers discovered that Dynabeads exhibit an unusually strong Raman signature, similar to a fluorescent tag, enabling rapid detection with this distinctive signature functioning as a "reporter." Detecting this signal quickly can confirm the existence of a target pathogen in a given sample within less than a second.

In a practical demonstration, the researchers mixed Dynabeads into vials containing Salmonella-contaminated water. These beads were magnetically isolated onto microscope slides, after which the researchers measured how light scattered through the fluid upon exposure to laser light. Within just half a second, the Dynabeads' Raman signature was detected, confirming the presence of bound Dynabeads and, consequently, Salmonella in the fluid. This novel technique surpasses conventional methods in speed and incorporates components that could be adapted into more compact, portable formats. The team is actively working on devising a portable device capable of rapidly detecting an array of bacterial pathogens. In particular, the researchers aim to apply this approach to critical conditions such as sepsis, where prompt pathogen detection is vital and existing lab tests may not rapidly fulfill this requirement.

“This technique would be useful in a situation where a doctor is trying to narrow down the source of an infection in order to better inform antibiotic prescription, as well as for the detection of known pathogens in food and water,” said study co-author Marissa McDonald, a graduate student in the Harvard-MIT Program in Health Sciences and Technology. “Additionally, we hope this approach will eventually lead to expanded access to advanced diagnostics in resource-limited environments.”

“There are a lot of cases, like in sepsis, where pathogenic cells cannot always be grown on a plate,” said Jongwan Lee, MIT Postdoctoral Associate and study co-author. “In that case, our technique could rapidly detect these pathogens.”

Related Links:
MIT 

New
Platinum Member
Flu SARS-CoV-2 Combo Test
OSOM® Flu SARS-CoV-2 Combo Test
Magnetic Bead Separation Modules
MAG and HEATMAG
POCT Fluorescent Immunoassay Analyzer
FIA Go
New
Gold Member
Automatic Nucleic Acid Extractor
GeneRotex 24

Print article

Channels

Clinical Chemistry

view channel
Image: The new ADLM guidance will help healthcare professionals navigate respiratory virus testing in a post-COVID world (Photo courtesy of 123RF)

New ADLM Guidance Provides Expert Recommendations on Clinical Testing For Respiratory Viral Infections

Respiratory tract infections, predominantly caused by viral pathogens, are a common reason for healthcare visits. Accurate and swift diagnosis of these infections is essential for optimal patient management.... Read more

Molecular Diagnostics

view channel
Image: The HelioLiver Dx test has met the coprimary and secondary study endpoints in the CLiMB trial (Photo courtesy of Helio Genomics)

Blood-Based Test Outperforms Ultrasound in Early Liver Cancer Detection

Patients with liver cirrhosis and chronic hepatitis B are at a higher risk for developing hepatocellular carcinoma (HCC), the most prevalent type of liver cancer. The American Association for the Study... Read more

Hematology

view channel
Image: The CAPILLARYS 3 DBS devices have received U.S. FDA 510(k) clearance (Photo courtesy of Sebia)

Next Generation Instrument Screens for Hemoglobin Disorders in Newborns

Hemoglobinopathies, the most widespread inherited conditions globally, affect about 7% of the population as carriers, with 2.7% of newborns being born with these conditions. The spectrum of clinical manifestations... Read more

Industry

view channel
Image: For 46 years, Roche and Hitachi have collaborated to deliver innovative diagnostic solutions (Photo courtesy of Roche)

Roche and Hitachi High-Tech Extend 46-Year Partnership for Breakthroughs in Diagnostic Testing

Roche (Basel, Switzerland) and Hitachi High-Tech (Tokyo, Japan) have renewed their collaboration agreement, committing to a further 10 years of partnership. This extension brings together their long-standing... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.