Credit: Максим Кукушкин
Researchers say they’ve developed a lens-free microscope that can detect the presence of cell-level abnormalities with the same accuracy as larger and more expensive optical microscopes.
The invention could lead to less expensive, more portable technology for performing examinations of tissue, blood, and other biomedical specimens, according to the researchers.
It may prove especially useful in remote areas and when large numbers of samples need to be examined quickly.
Aydogan Ozcan, PhD, of the University of California, Los Angeles, and his colleagues described their work with the microscope in Science Translational Medicine.
“This is a milestone in the work we’ve been doing,” Dr Ozcan said. “This is the first time tissue samples have been imaged in 3D using a lens-free, on-chip microscope.”
The device works by using a laser or light-emitting-diode to illuminate a tissue or blood sample that has been placed on a slide and inserted into the device. A sensor array on a microchip captures and records the pattern of shadows created by the sample.
The device processes these patterns as a series of holograms, forming 3-D images of the specimen and giving medical personnel a virtual depth-of-field view. An algorithm color codes the reconstructed images, making the contrasts in the samples more apparent than they would be in the holograms and making any abnormalities easier to detect.
Dr Ozcan’s team tested the device using blood samples containing sickle cell anemia, Pap smears that indicated cervical cancer, and tissue specimens containing cancerous breast cells.
In a blind test, a board-certified pathologist analyzed sets of specimen images that had been created by the lens-free technology and by conventional microscopes. The pathologist’s diagnoses using the lens-free microscopic images proved accurate 99% of the time.
Another benefit of the lens-free device, according to the researchers, is that it produces images that are several hundred times larger in area, or field of view, than those captured by conventional bright-field optical microscopes. This makes it possible to process specimens more quickly.
“While mobile healthcare has expanded rapidly with the growth of consumer electronics—cellphones in particular—pathology is still, by and large, constrained to advanced clinical laboratory settings,” Dr Ozcan said. “Accompanied by advances in its graphical user interface, this platform could scale up for use in clinical, biomedical, scientific, educational, and citizen-science applications, among others.”
