Spectroscopy technique speeds detection of bacterial growth in contained blood samples

March 21, 2016
A spectroscopy-based instrument monitors bacterial growth in contained blood samples noninvasively and in real time.

An international team of researchers at Zhejiang Normal University (Jinhua, China) and Umeå University (Sweden) has developed a technique based on a spectroscopy method to monitor bacterial growth in contained blood samples quickly, accurately, and noninvasively.

Related: Fluorescence detection method diagnoses bloodstream infection quickly

Microorganism growth is driven by many factors, so it is critical to be able to assess the quality of blood samples quickly and accurately. Without this ability, samples might need to be discarded or, alternatively, result in or worsen illnesses. Although bacterial blood contamination is rare, it does occur and has led to deaths. A rapid screening method could mean that a larger percentage of blood could be directly tested for bacteria.

Jie Shao, associate professor at the Institute of Information Optics at Zhejiang Normal University, explains that microorganism growth is always associated with the production of carbon dioxide (CO2), so assessing CO2 levels within, for example, closed compartments like bottles or bags would allow them to detect this growth quickly.

Several detection techniques are currently capable of rapid and accurate measurements of gas compositions. Those based on optical spectroscopy are most appealing because they're noninvasive, boast high sensitivity, provide instant responses, and are potentially useful for assessment of bacterial growth. So, the researchers developed an instrument based on a technique called tunable diode laser absorption spectroscopy (TDLAS), which combines all of these properties with ease of use and low cost, Shao says. What's more, it can achieve low detection limits on the order of parts per billion, and measure temperature, pressure, velocity, and mass flux.

The research team used their instrument—which includes a tunable diode laser as the light source, beam shaping optics, a sample to be investigated, receiving optics, and one or more detectors—to assess bacterial growth of various types of samples under a variety of conditions. By applying the technique to transparent containers of organic substances such as food items or medical samples, bacterial growth can be quickly evaluated.

In contrast with conventional and more invasive techniques that require contact with the tested items, the TDLAS method is truly noninvasive for monitoring—in real time—the status of food and medical supplies, or as a tool to determine under which environmental conditions bacterial growth is expected to be severe.

Next, the researchers plan to enhance the technique to allow for assessments of microbial growth in a large variety of samples, expanding beyond food items and medical supplies, Shao says.

Full details of the work appear in the journal Applied Optics; for more information, please visit http://dx.doi.org/10.1364/AO.55.002339.

About the Author

BioOptics World Editors

We edited the content of this article, which was contributed by outside sources, to fit our style and substance requirements. (Editor’s Note: BioOptics World has folded as a brand and is now part of Laser Focus World, effective in 2022.)

Sponsored Recommendations

How to Tune Servo Systems: The Basics

April 10, 2024
Learn how to tune a servo system using frequency-based tools to meet system specifications by watching our webinar!

Precision Motion Control for Sample Manipulation in Ultra-High Resolution Tomography

April 10, 2024
Learn the critical items that designers and engineers must consider when attempting to achieve reliable ultra-high resolution tomography results here!

Motion Scan and Data Collection Methods for Electro-Optic System Testing

April 10, 2024
Learn how different scanning patterns and approaches can be used in measuring an electro-optic sensor performance, by reading our whitepaper here!

How Precision Motion Systems are Shaping the Future of Semiconductor Manufacturing

March 28, 2024
This article highlights the pivotal role precision motion systems play in supporting the latest semiconductor manufacturing trends.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!