New system may improve diagnoses of chronic diseases

Scientists, including one of Indian origin, have developed a new system that could make it easier and less expensive to diagnose chronic diseases, particularly in remote areas without expensive lab equipment.

The technology created by researchers at University of California, Los Angeles (UCLA) in the US uses simple optical hardware and a lens-free microscope, as well as sophisticated algorithms that help reconstruct the images of tissue samples.

It could make much-needed diagnostic testing available and affordable for people in developing countries and remote areas that lack the expensive lab equipment currently used to perform tissue biopsies, researchers said.

Tissue biopsy is widely considered the gold standard for detecting diseases like cancer and inflammatory conditions. However, the test is relatively expensive and complex, and it requires the use of sophisticated facilities – a serious challenge in regions with limited resources.

"Although technological advances have allowed physicians to remotely access medical data to perform diagnoses, there is still an urgent need for a reliable, inexpensive means for disease imaging and identification - particularly in low-resource settings - for pathology, biomedical research and related applications," said Aydogan Ozcan, professor at UCLA.

The researchers, including Rajan Kulkarni, an assistant professor at UCLA, prepared tissue samples using a technique called Clarity, which makes tissue transparent, or "clears" it, using a chemical process that removes fat and leaves behind proteins and DNA.

The method typically requires fluorescent dyes, which can be costly, to stain the tissue samples, but one drawback of those dyes is that the staining tends to degrade over time, making it harder for scientists to gather information from it.

Instead, the researchers used coloured, light-absorbing dyes which can be used with regular microscopy tools without any noticeable signal loss over time, said Kulkarni.

The scientists developed a new device made of components that collectively cost just a few hundred dollars: a holographic lens-free microscope capable of producing 3D pictures with one-tenth the image data that conventional scanning optical microscopes need to do the same thing.

The method also allowed the scientists to use tissue samples that were 0.2 millimetres thick, more than 20 times thicker than a typical sample - a critical benefit of the new system because producing thinner tissue slices is difficult without sophisticated equipment, researchers said.

This also enables scientists to study a larger sample volume, which could help them to detect abnormalities earlier than they otherwise would.