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Clinical Laboratories and Pathology Groups

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Clinical Laboratories and Pathology Groups

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University of Queensland Researchers Isolate DNA and RNA with New ‘Dipstick Technology’ That May Allow Medical Laboratory Testing in Extremely Remote Locations such as Jungles

Researchers successfully isolated both plant and human RNA and DNA in the field, demonstrating the potential for their new dipstick technology to identify deadly bacteria, pathogens, and diseases in water, food, and even humans

Australian researchers at the University of Queensland (UQ) have developed an intriguing “dipstick” technology that might make it possible to use simple equipment to sequence DNA and RNA in the field. Among the potential applications that will interest clinical laboratory professionals is the ability for this technology to identify pathogens, both in humans and the environment.

Medical laboratories and anatomic pathologists are aware that gene sequencing (AKA, Nucleic Acid Sequencing) is the coming revolution in diagnostics. But the process is still costly and anchored to immovable technology that requires controlled environments and reliable resources. This promising new technology could make it simpler, cheaper, and faster to extract human DNA and RNA in settings outside a sophisticated core medical laboratory.

The UQ researchers developed technology that could affect how and where diagnostic tests for a whole range of pathogens are performed. For example, tests for bacteria such as E. coli in water supplies, pathogens in food, and diseases in humans currently are conducted in environmental and clinical laboratories. This new technology may allow such diagnostics to be done in extremely remote environments.

Isolating DNA/RNA in the Field

Jimmy Botella, PhD, Professor of Plant Biotechnology, and Michael Mason, PhD, Senior Post-doctoral researcher, both at the University of Queensland, led a team of researchers who published their findings in the journal PLOS Biology. The team developed a process they called “dipstick technology,” which allows DNA and RNA to be isolated quickly and without the use of specialized equipment.

They began by using the technology on particular plants, but soon found it could be used in many other situations.

“We found it had much broader implications as it could be used to purify DNA or RNA from human blood, viruses, fungi, and bacterial pathogens from infected plants or animals,” Botella noted in a press release.

The researchers’ objective was to investigate whether or not several different materials could be used to extract nucleic acids. “The first step in any application aiming to amplify DNA or RNA is the extraction of nucleic acids from a complex biological sample; a task traditionally requiring specialized equipment, trained technicians, and multiple liquid handling steps,” they wrote in the published study.

Holding the dipstick technology (from left) Dr. Michael Mason, Professor Jimmy Botella, and Yiping Zhou, all researchers at the University of Queensland in Brisbane, Australia. (Caption and photo copyright: University of Queensland.)

Their aim was to find a simpler process that required far less personnel and equipment. They found that cellulose-based filter paper could be used to bind nucleic acids. The filter paper, which was the control early in their investigation, even retained the nucleic acids through a purification process that removed contaminants. “We then adapted the cellulose filter to create a dipstick that can be used to purify nucleic acids from a wide range of plant, animal, and microbe samples in less than 30 seconds without the need for specialized equipment,” the researchers reported.

The team conducted its first tests on the plant species A. thaliana, a flowering plant found in Africa and Eurasia. However, wanting their dipstick technology to be useful in the field, they expanded their experiments to include various species of wheat, rice, soybean, tomato, and other plants. Citrus plants, known to be challenging, also were successfully tested.

The researchers then tested if their new technology would be useful for applications in humans, which is more complicated. HIV and hepatitis can be diagnosed using commercial kits, but those kits are not useful in many settings because the samples often require sophisticated manipulation. The researchers’ method—using cellulose paper and a one-minute wash—succeeded in amplification of the nucleic acid.

Performing Diagnostics in Hospitals, on Farms, and Even in the Jungle!

The University of Queensland’s commercialization company, UniQuest, has filed a patent application for the new technology. They are currently seeking partners to commercialize and sell the dipstick technology worldwide.

“Our dipsticks, combined with other technologies developed by our group, mean the entire diagnostic process from sample collection to final result could be easily performed in a hospital, farm, hotel room, or even a remote area such as a tropical jungle,” Botella noted in the press release.

The team conducted much of their field research on remote plantations in Papua New Guinea. They conducted tests on trees, livestock, human diseases, and to detect pathogens in food and water. “The dipstick technology makes diagnostics accessible to everyone,” Botella told Technology Networks.

Dipstick Diagnostics Not New to Point-of-Care Testing

As Modern Healthcare Executive noted, dipstick technology for various diagnostic purposes is not new, even though this particular application is, potentially, revolutionary. There are dipstick tests for everything from pregnancy to cholera. Also referred to as point-of-care testing (POCT), research and development of this technology has steadily grown, and as the UQ study shows, will likely continue.

In a paper published in Clinical Biochemistry Reviews, authors Andrew St. John, PhD, of ARC Consulting, and Christopher Price, MD, of the University of Oxford, noted, “Healthcare is changing, partly as a result of economic pressures, and also because of the general recognition that care needs to be less fragmented and more patient-centered.”

While there are certainly advantages to quick diagnostic tests that can be conducted in the field, there are some challenges, as well. Julie L. V. Shaw, PhD, Assistant Professor, Department of Pathology and Laboratory Medicine at The University of Ottawa, argues that “there are many challenges associated with POCT, mainly related to quality assurance,” in a paper she published in the journal Practical Laboratory Testing.

Technology will continue to develop and drive innovation and change in how diagnostics are performed and thus in how clinical laboratories operate. Various initiatives driving the industry toward personalized medicine and value-based care are sure to play a role, alongside new technology and other advancements.

With all of those changes, one thing remains critically important and that is the value of human understanding and innovation.

—Jillia Schlingman

Related Information:

Nucleic Acid Purification from Plants, Animals and Microbes in Under 30 Seconds

UQ Dipstick Technology Could Revolutionize Disease Diagnosis

Dipstick Technology Enables Rapid Diagnosis Anywhere

Existing and Emerging Technologies for Point-of-Care Testing

Practical Challenges Related to Point of Care Testing

The March of Technology Through the Clinical Laboratory and Beyond

CRISPR-Related Tool Set to Fundamentally Change Clinical Laboratory Diagnostics, Especially in Rural and Remote Locations

SHERLOCK makes accurate, fast diagnoses for about 61-cents per test with no refrigeration needed; could give medical laboratories a new diagnostic tool

Genetics researchers have been riveted by ongoing discoveries related to Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) for some time now and so have anatomic pathology laboratories. The diagnostic possibilities inherent in CRISPR have been established, and now, a new diagnostic tool that works with CRISPR is set to change clinical laboratory diagnostics in a foundational way.

The tool is called SHERLOCK, which stands for (Specific High-sensitivity Enzymatic Reporter unLOCKing). And it is causing excitement in the scientific community for several reasons:

  • It can detect pathogens in extremely small amounts of genetic matter;
  • Tests can be performed using urine and/or saliva rather than blood;
  • The tests are extremely sensitive; and they
  • Cost far less than the diagnostic tests currently in use.

In an article published in Science, researchers described SHERLOCK tests that can distinguish between strains of Zika and Dengue fever, as well as determining the difference between mutations in cell-free tumor DNA.

How SHERLOCK and CRISPR Differ and Why That’s Important

Scientists have long suspected that CRISPR could be used to detect viruses. However, far more attention has been given to the its genome editing capabilities. And, there are significant differences between how CRISPR and SHERLOCK work. According to the Science article, when CRISPR is used to edit genes, a small strip of RNA directs an enzyme capable of cutting DNA to a precise location within a genome. The enzyme that CRISPR uses is called Cas9 (CRISPR associated protein 9). It works like scissors, snipping the strand of DNA, so that it is either damaged or replaced by a healthy, new sequence.

SHERLOCK, however, uses a different enzyme—Cas13a (originally dubbed C2c2 by the researchers who discovered it). Cas13a goes to RNA, rather than DNA, and once it starts cutting, it doesn’t stop. It chops through any RNA it encounters. The researchers who developed SHERLOCK describe these cuts as “collateral cleavage.” According to an article published by STAT, “All that chopping generates a fluorescent signal that can be detected with a $200 device or, sometimes, with the naked eye.”

 

The screenshot above is from a video in which Feng Zhang, PhD (center), a Core Member of the Broad Institute at MIT and one of the lead researchers working on SHERLOCK, and his research team, explain the difference and value SHERLOCK will make in the detection of diseases like Zika. Click on the image above to watch the video. (Video copyright: Broad Institute/MIT.)

Early Stage Detection in Clinical Laboratories

A research paper published in Science states that SHERLOCK can provide “rapid DNA or RNA detection with attomolar sensitivity and single-base mismatch specificity.” Attomolar equates to about one part per quintillion—a billion-billion. According to the article on the topic also published in Science, “The detection sensitivity of the new CRISPR-Cas13a system for specific genetic material is one million times better than the most commonly used diagnostic technique.” Such sensitivity suggests that clinical laboratories could detect pathogens at earlier stages using SHERLOCK.

The Stat article notes that, along with sensitivity, SHERLOCK has specificity. It can detect a difference of a single nucleotide, such as the difference between the African and Asian strains of Zika (for example, the African strain has been shown to cause microcephaly, whereas the Asian strain does not). Thus, the combination of sensitivity and specificity could mean that SHERLOCK would be more accurate and faster than other diagnostic tests.

Clinicians in Remote Locations Could Diagnose and Treat Illness More Quickly

Perhaps one of the most important aspects of SHERLOCK is the portability and durability of the test. It can be performed on glass fiber paper and works even after the components have been freeze dried. “We showed that this system is very stable, so you can really put it on a piece of paper and it will survive. You don’t have to refrigerate it all the times,” stated Feng Zhang, PhD, in an interview with the Washington Post. Zhang is a Core Member of the Broad Institute at MIT and was one of the scientists who developed CRISPR.

The researchers note that SHERLOCK could cost as little as 61-cents per test to perform. For clinicians working in remote locations with little or no power, such a test could improve their ability to diagnose and treatment illness in the field and possibly save lives.

“If you had something that could be used as a screening test, very inexpensively and rapidly, that would be a huge advance, particularly if it could detect an array of agents,” stated William Schaffner, MD, Professor and Chair of the Department of Preventive Medicine at Vanderbilt University Medical Center, in the Post article. Schaffner describes the Broad Institute’s research as being “very, very provocative.”

The test could radically change the delivery of care in more modern settings, as well. “It looks like one significant step on the pathway [that] is the Holy Grail, which is developing point-of-care, or bedside detection, [that] doesn’t require expensive equipment or even reliable power,” noted Scott Weaver, PhD, in an article on Big Think. Weaver is a Professor and Director at the Institute for Human Infections and Immunity University of Texas Medical Branch in Galveston, Texas.

Just the Beginning

Anatomic pathologists and clinical laboratories will want to follow SHERLOCK’s development. It could be on the path to fundamentally transforming the way disease gets diagnosed in their laboratories and in the field.

According to the Post article, “The scientists have filed several US patent applications on SHERLOCK, including for uses in detecting viruses, bacteria, and cancer-causing mutations.” In addition to taking steps to secure patents on the technology, the researchers are exploring ways to commercialize their work, as well as discussing the possibility of launching a startup. However, before this technology can be used in medical laboratory testing, SHERLOCK will have to undergo the regulatory processes with various agencies, including applying for FDA approval.

—Dava Stewart

 

Related Information:

New CRISPR Tool Can Detect Tiny Amounts of Viruses

CRISPR Cousin SHERLOCK May Be Able to Track Down Diseases, Scientists Say

Nucleic Acid Detection with CRISPR-Cas13a/C2c2

A New CRISPR Breakthrough Could Lead to Simpler, Cheaper Disease Diagnosis

Meet CRISPR’s Younger Brother, SHERLOCK

Trends in Genomic Research That Could Impact Clinical Laboratories and Anatomic Pathology Groups Very Soon

Pathologists and Clinical Laboratories May Soon Have a Test for Identifying Cardiac Patients at Risk from Specific Heart Drugs by Studying the Patients’ Own Heart Cells

Patent Dispute over CRISPR Gene-Editing Technology May Determine Who Will Be Paid Licensing Royalties by Medical Laboratories

University of Texas Researchers Develop New Techniques in Genetic Testing to Improve Clinical Laboratory Results through RNA

Innovative technological advances could potentially provide clinical laboratories, pathology groups, and medical researchers with improved methodologies for designing, performing, and analyzing lab tests that use genetic information

Researchers at the University of Texas at Austin (UT Austin) have developed an innovative new enzyme that promises to improve the methods and tools used by pathology groups and clinical laboratories when conducting genetic testing.

The enzyme enables the reproduction of large quantities of Ribonucleic acid (RNA) to be accurately duplicated. It also can perform reverse transcription and scrutinize itself while copying genetic information, which will enable both researchers and clinical laboratories to improve the accuracy of gene sequencing where RNA is involved.

The team published their findings in Science, the academic journal of The American Association for the Advancement of Science (AAAS) and filed for a provisional patent for the new sequence of the discovered enzyme. (more…)

University of Pennsylvania Researchers Develop $2 Zika Proof-of-Concept Test That Needs Neither Electricity Nor a Clinical Laboratory to Return Accurate Results

Using 3D printing and a chemical heat source, University of Pennsylvania researchers have created a proof-of-concept for an affordable Zika test that returns results in just 40 minutes

There’s a gap in Zika virus testing that researchers at the University of Pennsylvania hope to fill. That gap is a point-of-care test for the Zika virus that can produce a fast and accurate result, whether in developed nations or in developing countries that don’t have many state-of-the art clinical laboratories.

Although numerous Zika virus tests have earned Emergency Use Authorizations from the US Food and Drug Administration (FDA), gold standard detection is still limited to medical laboratories. To date, the FDA’s list of current and terminated Emergency Use Authorizations include no point-of-care options to help medical professionals quickly screen patients for Zika infection.

As noted by the Center for Disease Control and Prevention’s “Interim Guidance for Interpretation of Zika Antibody Test Results,” the antibodies that indicate Zika virus activity also share similarities with other flavivirus viruses. Of particular note is similarities with Dengue virus—a virus prevalent in many of the areas in which Zika is found. (more…)

New Fast, Inexpensive, Mobile Device Accurately Identifies Healthcare-Acquired Infections and Communicates Findings to Doctors’ Smartphones and Portable Computers

Use of these new technologies creates opportunities for clinical laboratories and pathologists to add more value when collaborating with physicians to advance patient care

Ongoing improvements in point-of-care testing are encouraging one major academic medical center to apply this mode of testing to the diagnosis of hospital-acquired infections (HAIs). This development should be of interest to clinical laboratory professionals and pathologists, since it has the potential to create a different way to identify patients with HAIs than medical lab tests done in the central laboratory.

Massachusetts General Hospital (MGH), Harvard Medical School’s (HMS’) largest teaching hospital, has developed a prototype diagnostic system that works with doctors’ smartphones or mobile computers. The hand-held system can identify pathogens responsible for specific healthcare-acquired infections (HAIs) at the point of care within two hours, according to an MGH statement.

The researchers noted that 600,000 patients develop HAIs each year, 10% of which die, and that costs related to HAIs can reach $100 to $150 billion per year. However, as Dark Daily reported, the Centers for Medicare and Medicaid Services (CMS) does not reimburse hospitals for certain HAIs. (See Dark Daily, Consumer Reports Ranks Smaller and Non-Teaching Hospitals Highest in Infection Prevention,” October, 30, 2015.) Thus, the critical need to identify from where the infection originated, which generates a significant proportion of samples tested at the clinical laboratories of the nation’s hospitals and health systems.

Therefore, pathologists and medical laboratory scientists will understand that shifting some of that specimen volume to point-of-care testing will change the overall economics of hospital laboratories.

Smartphone-based Genetic Test for HIAs

The MGH research team created a way to do accurate genetic testing in a simple device powered by a system they call Polarization Anisotropy Diagnostics (PAD). The system measures changes in fluorescence anisotropy through a detection probe’s recognition of bacterial nucleic acid, reported Medscape Medical News. More than 35 probes for detecting bacterial species and virulence factors are available.

Optical test cubes are placed on an electronic base station that transmits data to a smartphone or computer, where results are displayed. “In a pilot clinical test, PAD accuracy was comparable to that of bacterial culture. In contrast to the culture, the PAD assay was fast (under two hours), multiplexed, and cost effective (under $2 per assay), wrote the MGH researchers in the journal Science Advances. (more…)

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