The microscope inspired by a barcode scanner

Engineers at the Australian National University (ANU) have built a microscope that can film moving blood cells and neurons in living animals.

Writing in the Journal of Biophotonics, Dr Steve Lee and colleagues explained that commercial microscopy systems make use of tandem scanning, ie, either slow or fast scanning. Looking to improve on this, the researchers constructed a control system capable of delivering a dynamic line scanning speed ranging from 2.7 to 27 kHz and achieving variable frame rates from 5 to 50 Hz.

“What we’ve done is engineer a flexible imaging platform allowing biologists to capture both slow and fast processes as required,” said Dr Lee, lead researcher on the project.

So how did they do it? As stated by Dr Lee, the microscope used technology similar to retail barcode scanners and office laser printers.

In barcode scanners, a laser beam bounces off a spinning polygon mirror with around 10 mirror facets, allowing it to scan across a sample very quickly. A barcode scanner registers a sequence of patterns to identify a product.

Dr Lee’s microscope used a more powerful laser beam as the light source and up to 36 mirror facets to scan the laser beam across the biological sample in a few thousandths of a second. He said the team “modernised the polygon mirror microscopy system with advanced electronics and software controls to enable real-time imaging applications, with up to 800 frames per second”.

“We achieve the same imaging resolution of conventional scanning microscopes on the market but at double the speed,” he said.

Dr Lee said the microscope’s flexibility means it can speed up or slow down to capture the slow moving cells in a blood stream or live neurons firing rapidly in the brain. It can thus be used by scientists to analyse a variety of complex medical problems, he said, “ranging from blood disorders and cancer to neurological disorders”.

Image caption: Yongxiao Li and Dr Steve Lee with the advanced microscope they built. Image credit: Jack Fox, ANU.