New lens-free microscope to detect cancer

Researchers have developed a lens-free microscope that can be used to detect the presence of cancer or other cell-level abnormalities with the same accuracy as larger and more expensive optical microscopes.
The invention could lead to less expensive and more portable technology for performing common examinations of tissue, blood and other biomedical specimens, researchers said.
It may prove especially useful in remote areas and in cases where large numbers of samples need to be examined quickly.
"This is the first time tissue samples have been imaged in 3D using a lens-free on-chip microscope," Aydogan Ozcan, from the University of California, Los Angeles (UCLA).

The invention is the first lens-free microscope that can be used for high-throughput 3-D tissue imaging - an important need in the study of disease, researchers said.
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 - the same type of chip that is used in digital cameras, including cellphone cameras - 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 colour 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.
Ozcan's team tested the device using Pap smears that indicated cervical cancer, tissue specimens containing cancerous breast cells, and blood samples containing sickle cell anaemia.
In a blind test, a board-certified pathologist analysed 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 per cent of the time.
Another benefit of the lens-free device 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, which makes it possible to process specimens more quickly.

The research was published in the journal Science Translational Medicine.