Small handheld device uses sound waves to detect certain clinical laboratory biomarkers in blood samples
University of Colorado Boulder researchers have developed a novel technology that uses sound waves to test for biomarkers in blood samples. In addition to being very easy to use, the handheld device is portable, highly sensitive, and delivers results in minutes. Though not ready for clinical use, this is yet another example of how researchers are developing faster diagnostic tests that can be performed in near-patient settings, and which do not have to be done in core laboratories, shortening time to answer.
The small instrument—referred to as an “acoustic pipette”—delivers sound waves to tiny particles within the device called “functional negative acoustic contrast particles” (fNACPs). These particles are cell-sized balls that can be customized with different coatings to identify specific biomarkers—such as viruses or proteins—in tiny blood samples, according to a news release.
To operate the device, the custom fNACPs are mixed with a drop of blood and then placed inside the acoustic pipette. The mixture is then blasted with sound waves, which forces particles carrying certain biomarkers to one side of the chamber where they are trapped while the rest of the blood is expelled. The captured biomarkers are then labeled with fluorescent tags and examined with lasers to determine how much of a specific biomarker is present.
“We’re basically using sound waves to manipulate particles to rapidly isolate them from a really small volume of fluid,” said Cooper Thome (above), PhD candidate in Chemical and Biological Engineering at UC Boulder and first author of the study in a news release. “It’s a whole new way of measuring blood biomarkers,” he added. Should further studies validate this approach, clinical laboratories may be able to use this technology to perform diagnostic tests with smaller volumes of patient samples. (Photo copyright: University of Colorado Boulder.)
Blood Testing Quickly and in Multiple Settings
To test their invention, the UC Boulder researchers examined antibodies against a protein called ovalbumin, which is found in egg whites and often used in the development of various vaccines. The scientists discovered that their device could detect the antibodies even in low amounts.
Current rapid tests known as lateral-flow assays can detect specific biomarkers in blood or urine samples but cannot determine how much of the biomarker is present. Enzyme-linked immunotherapy assays (ELISA), the leading clinical laboratory blood test, requires expensive equipment and can take hours to days for results to be received.
With UC Boulder’s new handheld device, tiny blood samples collected from a single finger prick could ensure accurate test results are available quickly at the point of care as well as outside of traditional healthcare settings. This would greatly benefit people in developing nations and underserved communities and may help ease test anxiety for individuals who are apprehensive about traditional blood tests.
“We’ve developed a technology that is very user friendly, can be deployed in various settings, and provides valuable diagnostic information in a short time frame,” said Wyatt Shields IV, PhD, Assistant Professor, Department of Chemical and Biological Engineering, UC Boulder, and senior author of the research in the news release.
“In our paper, we demonstrate that this pipette and particle system can offer the same sensitivity and specificity as a gold-standard clinical test can but within an instrument which radically simplifies workflows,” he added. “It gives us the potential to perform blood diagnostics right at the patient’s bedside.”
The graphic above, taken from UC Boulder’s published paper, illustrates how “fNACPs capture target biomarkers from whole blood samples. fNACPs are purified from blood components by acoustic trapping and captured biomarkers are labeled with a fluorescent antibody within the acoustic pipette. fNACP fluorescence is then measured to determine biomarker presence and concentration.” (Graphic/caption copyright: University of Colorado Boulder.)
Not Like Theranos
The authors of the UC Boulder study are cognizant of some skepticism surrounding the field of biosensing, especially after the downfall of Theranos. The scientists insist their technology is different and based on systematic experiments and peer-reviewed research.
“While what they (Theranos) claimed to do isn’t possible right now, a lot of researchers are hoping something similar will be possible one day,” said Thome in the news release. “This work could be a step toward that goal—but one that is backed by science that anybody can access.”
The device is still in its initial proof-of-concept stage, but the UC Boulder scientists have applied for patents for the apparatus and are searching for ways to scale its use and expand its capabilities.
“We think this has a lot of potential to address some of the longstanding challenges that have come from having to take a blood sample from a patient, haul it off to a lab, and wait to get results back,” Shields noted.
More research, studies, and regulatory reviews will be needed before this technology becomes available for regular, widespread use. But UC Boulder’s new blood testing device is another example of a research team using novel technology to test for known biomarkers in ways that could improve standard clinical laboratory testing.
Teams from multiple Swedish organizations are investigating the relationship of protein-coding genes to antibodies
Scientists in Sweden are discovering new ways to map the expression of genes in cells, tissues, and organs within the human body thanks to advances in molecular profiling. Their study has successfully combined the analysis of single-cell transcriptomics with spatial antibody-based protein profiling to produce a high-resolution, single-cell mapping of human tissues.
The data links protein-coding genes to antibodies, which could help researchers develop clinical laboratory tests that use specific antibodies to identify and target infectious disease. Might this also lead to a new menu of serology tests that could be used by medical laboratories?
This research is another example of how various databases of genetic and proteomic information—different “omics”—are being combined to produce new understanding of human biology and physiology.
In a Human Protein Atlas (HPA) project press release, Director of the HPA consortium and Professor of Microbiology at Royal Institute of Technology in Stockholm, Mathias Uhlén, PhD, said, “The [Science Advances] paper describes an important addition to the Human Protein Atlas (HPA) which has become one of the world’s most visited biological databases, harboring millions of web pages with information about all the human protein coding genes.”
“We are excited that the new open-access Single Cell Type section constitutes a unique resource for studying the cell type specificity and exact spatial localization of all our proteins”, said Cecilia Lindskog, PhD (above), Head of the HPA Tissue Atlas and Associate Professor, Experimental Pathology, Uppsala University, in the Protein Atlas press release. Medical laboratories may soon have new serology tests to perform that were developed based on HPA data. (Photo copyright: Human Uterus Cell Atlas.)
Distinct Expression Clusters Consistent to Similar Cell Types
To perform their research, the scientists mapped the gene expression profile of all protein-coding genes across different cell types. Their analysis showed that there are distinct expression clusters which are consistent to cell types sharing similar functions within the same organs and between organs of the human body.
The scientists examined data from non-diseased human tissues and organs using three main criteria:
Publicly available raw data from human tissues containing good technical quality with at least 4,000 cells analyzed and at least 20 million read counts by the sequencing for each tissue.
High correlation between pseudo-bulk transcriptomics profile from the scRNA-Seq data and bulk RNA-Seq generated as part of the Human Protein Atlas (HPA).
High correlation between the cluster-specific expression and the expected expression pattern of an extensive selection of marker genes representing well-known tissue- and cell type-specific markers, including both markers from the original publications and additional markers used in pathology diagnostics.
According to the HPA press release, “across all analyzed cell types, almost 14,000 genes showed an elevated expression in particular cell types, out of which approximately 2,000 genes were found to be specific for only one of the cell types.”
The press release also states, “cell types in testis showed the highest numbers of cell type elevated genes, followed by ciliated cells. Interestingly, only 11% of the genes were detected in all analyzed cell types suggesting that the number of essential genes (‘house-keeping’) are surprisingly few.”
Omics-based Biomarkers for Accurate Diagnosis of Disease
The Human Protein Atlas is the largest and most comprehensive database for spatial distribution of proteins in human tissues and cells. It provides a valuable tool for researchers who study and analyze protein localization and expression in human tissues and cells.
Ongoing improvements in gene sequencing technologies are making research of genes more accurate, faster, and more economical. Advances in gene sequencing also could help medical professionals discover more personalized care for patients leading to improved outcomes. A key goal of precision medicine.
One of the conclusions to be drawn from this work is that clinical laboratories and anatomic pathology groups will need to be able to handle immense amounts of data, while at the same time having the capabilities to analyze that data and identify useful patterns that can help diagnose patients earlier and more accurately.
Of interest to clinical pathologists is the finding that sequencing the genomes of Humans and Neanderthals revealed a link between severity of COVID-19 infections and Neanderthal DNA
Genetic scientists from the University of California Santa Cruz have learned that just 7%—or less—of our DNA is unique to the human species, with the remainder of our genomes coming from other archaic species, such as Neanderthal and Denisovan.
Why should this matter to pathologists and clinical laboratories? Because a broader knowledge of how DNA evolves may help researchers and healthcare providers better understand how a modern family’s DNA can change over generations. In turn, these insights may lead to precision medicine tools for personalized diagnosis and treatment.
“We find that a low fraction, 1.5 to 7%, of the human genome is uniquely human, with the remainder comprising lineages shared with archaic hominins from either ILS [incomplete lineage sorting] or [genetic] admixture,” wrote the paper’s authors.
To complete their study, the researchers used DNA extracted from fossils of Neanderthals and Denisovans, as well as genetic information from 279 people from various locations around the world.
One goal was to determine what part of a modern human’s genome is truly unique. Though only a small percentage of our entire genome, those portions are important.
“We can tell those regions of the genome are highly enriched for genes that have to do with neural development and brain function,” Richard Green, PhD, Associate Professor of Biomolecular Engineering at the University of California Santa Cruz and co-author of the paper, told the Associated Press (AP).
In addition to highlighting what makes modern humans unique as a species, the study also suggests, “That we’re actually a very young species. Not that long ago, we shared the planet with other human lineages,” said Joshua Akey, PhD, Professor of Ecology and Evolutionary Biology and the Lewis-Sigler Institute for Integrative Genomics at Princeton University. Akey co-authored the Science Advances research paper.
Human/Neanderthal Genetic Overlap
The genetic research being conducted at the University of California Santa Cruz is just the most recent in a flurry of studies over the past decade investigating the Neanderthal genome. Most of these studies point to the vast similarities between humans and Neanderthals, but also to how similar humans are to each other.
“Humans have more than three billion letter pairs of DNA in their genome: It turns out less than 2% of that spells out around 20,000 specific genes, or sets of instructions that code for the proteins that make our tissues,” wrote zooarcheologist Anna Goldfield, PhD (above), Adjunct Instructor Cosumnes River College in Sacramento, Calif., and at the University of California, Davis, in Sapiens. “All humans share the same basic set of genes (we all have a gene for earwax consistency, for example), but there are subtle variations in the DNA spelling of those genes from individual to individual that result in slightly different proteins (sticky earwax versus dry earwax) … Overall, any given human being is about 99.9% similar, genetically, to any other human being,” she added. It is those variations that could lead to precision medicine treatments, personalized drug therapies, and clinical laboratory tests that inform physicians about relevant genetic variations. (Photo copyright: Boston University.)
Practically Everyone Has Neanderthal DNA
Understanding that humans and Neanderthals are 93-98.5% similar genetically may—or may not—come as a surprise. In delving into those similarities and differences researchers are making interesting and potentially important discoveries.
For example, researchers have studied a gene that occurs in both modern humans and Neanderthal fossils that has to do with how the body responds to carcinogenic hydrocarbons, such as smoke from burning wood. Neanderthals were far more sensitive to the carcinogens, but also had more genetic variants, such as single-nucleotide polymorphisms, that could neutralize their effects.
Most modern humans carry some Neanderthal DNA. For some time, scientists thought that Africans likely did not carry Neanderthal DNA, since ancient people tended to migrate out of Africa and met Neanderthals in Europe. More recent research, however, shows that migration patterns were more complex than previously thought, and that the ancient people migrated back to Africa bringing Neanderthal DNA with them.
“Our results show this history was much more interesting and there were many waves of dispersal out of Africa, some of which led to admixture between modern humans and Neanderthals that we see in the genomes of all living individuals today,” Akey told CNN.
Neanderthal DNA and COVID-19
Researchers have found that having Neanderthal DNA may affect the health of modern people who carry it. Perception of pain, immune system function, and even hair color and sleeping patterns have been associated with having Neanderthal DNA.
Scientists have even found a potential link between severe COVID-19 infection and Neanderthal DNA, CNN reported.
The researchers added, “It turns out that this gene variant was inherited by modern humans from the Neanderthals when they interbred some 60,000 years ago. Today, the people who inherited this gene variant are three times more likely to need artificial ventilation if they are infected by the novel coronavirus SARS-CoV-2.”
Of course, these links and associations are preliminary science. John Capra, PhD, Research Associate Professor of Biological Sciences and Associate Professor of Biomedical Informatics at the University of California, San Francisco says, “We can’t blame Neanderthals for COVID. That’s a damaging response, and that’s why I want to emphasize so much [that] the social and environmental factors are the real things that people should be worrying about,” he told CNN.
“That said,” he continued, “as a geneticist, I think it is important to know the evolutionary history of the genetic variants we find that do have effects on traits. The effects of Neanderthal DNA traits are detectable, but they’re modest.”
Nevertheless, genetic scientists agree that understanding the genetic roots of disorders could lead to breakthroughs that result in new types of clinical laboratory tests designed to guide precision medicine treatments.
