Nav: Home

When a spinning toy meets hydrodynamics: Point-of-care technology is set in motion

May 18, 2020

About 60% of women will experience urinary tract infection (UTI) at least once in their lifetime. With antibiotic-resistant organisms increasing, UTI is likely to bring more of the health and economic burden. To turn things around, point of care testing (POCT) technology has been identified as a breakthrough in diagnosing suspected UTI patients. POCT enables staff to provide real-time, lab-quality patient care when and where it is needed. Despite recent advances by POCT, every year millions of people die of treatable illness such as UTI and of the lack of diagnosis in developing parts of the world. It is a pressing need for technologies to bridge this existing gap.

Researchers at the Center for Soft and Living Matter, within the Institute for Basic Science (IBS, South Korea), reported a diagnostic fidget spinner (Dx-FS) that allows for highly sensitive and rapid diagnosis and prescription only with hand power. Fidget spinners are boomerang-shaped toys whose ball bearings reduce friction and allow things to rotate freely for a long time (Figure 1A). One flick of the fidget with a finger sets the gadget in motion. By exploiting the centrifugal force derived from the design of a fidget spinner and their novel mechanism called, a fluid assisted separation technology (FAST), the research team optimized the fluidic dynamics in Dx-FS. This mechanism enables the Dx-FS to work just with one or two spins by hand and to produce 100 times more enriched pathogens that can be easily seen by naked-eyes without the need of bacteria culture (Figure 1B).

Conventional approach for the diagnostics of the infectious disease require time-consuming cell culture as well as modern laboratory facilities. Worse yet, typical bacterial cell enrichment requires huge force and it is prone to membrane fouling or clogging due to the pressure imbalance in the filtration chamber. "Though the centrifugal force serves as an "engine" of the device, the force is felt more strongly in the outer path as it acts outwardly away from the center of rotation. The imbalanced impact of the centrifugal force keeps some of the sample left in the membrane. We utilized hydrodynamic forces that acts vertically to the centrifugal force by filling the filter membrane with liquid before the spinning process. This minimized the pressure drop and brought the uniform pressure balance throughout the entire area of the membrane. This allowed for maximized bacterial cell enrichment efficiency while minimizing the force needed for the filtration. Therefore, one or two spins were enough to filter 1 mL of sample despite large variation in the spin speed among different operators with different hand power (Figure 1C)." explains professor CHO Yoon-Kyoung, the corresponding author of the study.

In FAST-based particle separation, the fluid flow caused by centrifugal force is in a direction perpendicular to the filtration flow through the membrane. In addition, the drainage chamber underneath the membrane remains fully filled with the liquid during the entire filtration process. This is achieved by placing a buffer solution in the bottom chamber of the membrane prior to the spinning process, which ensures uniform filtration across the entire area of the membrane and significantly reduces the hydrodynamic resistance.

The research team verified Dx-FS can perform "sample-in-answer-out" analyses. The research team tested urine samples from 39 UTI suspects in Tiruchirappalli, India. Compared to the gold-standard culture method, which has a relatively long turnaround time, Dx-FS provided a comparable answer on site in 50 minutes. The experiment shows 59% of UTI suspects were over/under-treated for antibiotics, which may be saved by using Dx-FS (Figure 2). Further, they performed a rapid antimicrobial susceptibility test (AST) for two antimicrobial drugs on 30 UTI patients using Dx-FS. The test produced 100% accurate results within 120 minutes (Figure 3).

Overall, this simple, hand-powered, portable device allows rapid enrichment of pathogens from human urine samples, showing high potential for future low-cost POCT diagnostic applications. A simple tool like Dx-FS provides UTI management and prevention of resistance in low resource settings.

Institute for Basic Science

Related Membrane Articles:

What membrane can do in dealing with radiation
USTC recently found that polymethylmethacrylate (PMMA) and polyvinyl chloride (PVC) can release acidic substance under γ radiation, whose amount is proportional to the radiation intensity.
Using light's properties to indirectly see inside a cell membrane
Using properties of light from fluorescent probes is at the heart of a new imaging technique developed at Washington University's McKelvey School of Engineering that allows for an unprecedented look inside cell membranes.
Cells relax their membrane to control protein sorting
The tension in the membrane of cells plays an important role in a number of biological processes.
How are misfolded membrane proteins cleared from cells by "reubiquitinase"?
Chinese researchers recently discovered a protein quality control mechanism called ''reubiquitination'', which could promote the elimination of misfolded membrane proteins, minimize their dwell time in cells, and thereby reduce their probability to form toxic aggregates in human body.
Across the cell membrane
Aquaporins and glucose transporters facilitate the movement of substances across biological membranes and are present in all kingdoms of life.
First simulation of a full-sized mitochondrial membrane
Scientists from the University of Groningen have developed a method that combines different resolution levels in a computer simulation of biological membranes.
New self-forming membrane to protect our environment
A new class of self-forming membrane has been developed by researchers from Newcastle University, UK.
Cell membrane proteins imaged in 3D
A team of scientists including researchers at the National Synchrotron Light Source II have demonstrated a new technique for imaging proteins in 3D with nanoscale resolution.
Quantum-entangled light from a vibrating membrane
Researchers from the Quantum Optomechanics group at the Niels Bohr Institute, University of Copenhagen, recently entangled two laser beams through bouncing them off the same mechanical resonator, a tensioned membrane.
Visualizing molecular patterns of membrane TNF receptors
Whether a sick cell dies, divides, or travels through the body is regulated by a sophisticat-ed interplay of signal molecules and receptors on the cell membrane.
More Membrane News and Membrane Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at     You can read The Transition Integrity Project's report here.