UC Davis Researchers Develop Microscope That Uses Ultraviolet Light for Diagnosis, Eliminates Need for Traditional Histology Slide Preparation
MUSE microscope speeds up some anatomic pathology laboratory processes and removes exposure to toxic fixative chemicals
Because they handle tissue specimens, histotechnologists, anatomic pathologists, and hospital nurses are exposed to deadly chemicals such as formaldehyde, formalin, Xylene, and Toluene. The risks associated with these chemicals has been covered regularly by Dark Daily as recently as 2018 and as far back as 2011. (See, “Europe Implements New Anatomic Pathology Guidelines to Reduce Nurse Exposure to Formaldehyde and Other Toxic Histology Chemicals,” January 3, 2018; and, “Health of Pathology Laboratory Technicians at Risk from Common Solvents like Xylene and Toluene,” July 5, 2011.)
Now, scientists at the University of California at Davis (UC Davis) have developed a microscope that uses ultraviolet light (UV) to illuminate tissue samples. The UV microscope removes the need for traditional histology processes involved with preparation of tissue to produce conventional slides and makes it possible for anatomic pathologists to evaluate tissues without formalin fixation, according to a UC Davis news release.
“Here, we introduce a simple, non-destructive slide-free technique that, within minutes, provides high-resolution diagnostic histological images resembling those obtained from conventional hematoxylin and eosin histology,” the researchers wrote in their paper, published in Nature Biomedical Engineering.
High-resolution Biopsy Images in Minutes
The UV microscope relies on technology that UC Davis researchers dubbed MUSE, which stands for Microscopy with Ultraviolet Surface Excitation. According to the researchers, MUSE produces high-resolution images of biopsies and other fresh tissue samples that are ready for a pathologist’s review within minutes.
“MUSE eliminates any need for conventional tissue processing with formalin fixation, paraffin embedding, or thin-sectioning. It doesn’t require lasers, confocal, multiphoton, or optical coherence tomography instrumentation. And the simple technology makes it well-suited for deployment wherever biopsies are obtained and evaluated,” stated Richard Levenson, MD, MUSE Microscopy CEO, Professor, and Vice Chair for Strategic Technologies in the Department of Pathology and Laboratory Medicine at UC Davis, in the news release.
Ultraviolet microscopy is distinguished by its ability to magnify samples and enable views with greater resolution. This is due to the shorter wavelength of ultraviolet light, which improves image resolution beyond the diffraction limit of optical microscopes using normal white light, according to News Medical.
The unique ultraviolet light microscope tool may soon enable clinical laboratories and anatomic pathology groups to accurately report on biopsies to physicians and patients faster, for less money, and without exposure to deadly chemicals. This would be timely considering the pressure on the pathology industry to switch to value-based reimbursement from fee-for-service billing, and to embrace personalized medicine.
“It has become increasingly important to submit relevant portion of often tiny tissue samples for DNA and other molecular functional tests,” notes Richard Levenson, MD, MUSE Microscopy CEO, Professor, and Vice Chair for Strategic Technologies in the Department of Pathology and Laboratory Medicine at UC Davis, shown above with MUSE. “Making sure that the submitted material actually contains tumor in sufficient quantity is not always easy and sometimes just preparing conventional microscope slices can consume most of or even all of small specimens. MUSE is important because it quickly provides images from fresh tissue without exhausting the sample.” (Photo and caption copyright: UC Davis.)
MUSE is being commercialized and investors sought by MUSE Microscopy, Inc.
Traditional Microscopy is Time-Consuming, Hazardous, Expensive
Light microscopy, a time-honored technology, has been available to pathologists for more than 200 years. It is the cornerstone for cancer diagnostics and pathology, the UC Davis researchers acknowledged. But it requires time-consuming and expensive processes, which are especially glaring in a resource-challenged healthcare industry, they pointed out.
“Histological examination of tissues is central to the diagnosis and management of neoplasms and many other diseases. However, commonly used bright-field microscopy requires prior preparation of micrometer-thick tissue sections mounted on glass slides—a process that can require hours or days, contributes to cost, and delays access to critical information,” they wrote in their paper.
“MUSE promises to improve the speed and efficiency of patient care in both state-of-the art and low-resource settings, and to provide opportunities for rapid histology in research,” they continued.
No Histology Slide Preparation Needed
MUSE developers also called attention to the use of hazardous chemicals, such as formalin, in lab processes, which has been linked to cancers including myeloid leukemia, nasopharyngeal cancer, and sinonasal cancer, according to a National Academy of Sciences report. Still, more than 300 million slides are prepared in the US each year at a cost of several billion dollars to the healthcare industry, according to the MUSE Website.
MUSE, however, penetrates tissue samples by using ultraviolet light at short wavelengths—below the 300-nanometer range. The MUSE ultraviolet microscope can reach several microns-deep into tissues.
That’s enough, the researchers claim, to be comparable with the thickness of tissue slices anatomic pathologists use with traditional microscope slides. However, MUSE requires no conventional tissue processing associated with histology slides.
How Does it Work?
MUSE is comprised of an optical system with UV light-emitting diodes (LEDs), a UV compatible stage, and a conventional microscope. That’s according to Photonics Online, which described the process:
- “UV light at 280 nanometer spectral range illuminates about one square millimeter of specimen;
- “Surface is limited to a few nanometers deep to make high-contrast images possible;
- “Excitation light, at sub-300 nanometer spectral region, elicits bright emission from tissue specimens;
- “Specimens, which were stained with conventional florescent dyes, emit photons;
- “Photons are captured using glass-based microscope optics;
- “A Python programing language solution, with a graphics unit, converts MUSE images in real-time;
- “Images are comparable to the hematoxylin and eosin versions histologists and pathologists are accustomed to.”
The result, according the MUSE website, “is stunning detailed images conveying a degree of resolution, structure, and depth unachievable until now by any single technology.”
Other Alternative Histology Processes Under the Microscope
MUSE is not the only approach being studied that could create cellular images without sectioning tissue samples. Anatomic and histopathology laboratory leaders looking to differentiate their labs should keep watch on the development of MUSE and other alternatives to current histology methods, especially once these new devices become green-lighted by the Food and Drug Administration (FDA) for use in patient care.
—Donna Marie Pocius
Related Information:
Microscope That Uses Ultraviolet Instead of Visible Light Emerging as Powerful Diagnostic Tool
Microscope with Ultraviolet Surface Excitation for Rapid Slide-Free Histology
Ultraviolet Microscope to Dramatically Speed-up Lab Tests
What is Ultraviolet Microscopy?
Health of Pathology Laboratory Technicians at Risk from Common Solvents like Xylene and Toluene
