A team of researchers from Australia and the United States has demonstrated a new multispectral microscope capable of processing the largest microscopic image ever created. Nearly 17 billion pixels representing 13 individual colour channels can be handled in a single image.
The results have been published in Optica, a journal of The Optical Society.
The team has said this level of multicolour detail is essential for studying the impact of experimental drugs on biological samples and is an important advancement over traditional microscope designs, which have fallen short when it comes to imaging large, spectrally diverse samples.
The new instrument can simultaneously process large amounts of data, thus addressing a major bottleneck in pharmaceutical research: rapid, data-rich biomedical imaging.
By merging data simultaneously collected by thousands of microlenses – optical elements each smaller than the width of a human hair – this new multispectral microscope is able to produce a continuous series of datasets that essentially reveal how much of multiple colours are present at each point in a single biological sample.
‘Pharmaceutical research is awash with cutting-edge equipment that tries to image what is happening at the cellular level and smaller,’ said Antony Orth, a researcher with the ARC Centre for Nanoscale BioPhotonics, RMIT University in Melbourne, Australia. ‘We recognised that the microscopy part of the drug development pipeline was much slower than it could be and designed a system specifically for this task.’
The approach initially presented a challenge in the data pipeline. The raw data is in the form of one megapixel images recorded at 200 frames per second; a data rate much higher than current microscopes. This required the team to capture and process a tremendous amount of data each second.
Over time, the availability and prices of fast cameras and fast hard drives have come down considerably, allowing for a much more affordable and efficient design. The current limiting factor is loading the recorded data from hard drives to active computer memory to produce an image. The researchers estimate that an active memory of about 100 gigabytes to store the raw dataset would improve the entire process even further.
For example, to study the impact of a new cancer drug it’s essential to determine if a specific drug kills cancer cells more often than healthy cells. This requires testing the same drug on thousands to millions of cells with varying doses and under different conditions, which is normally a very time-consuming and labour-intensive task.
The new microscope speeds up this process while also looking at many different colours at once. ‘This is important because the more colours you can see, the more insightful and efficient your experiments become,’ noted Orth. ‘Because of this, the speed-up afforded by our microscope goes beyond just the improvement in raw data rate.’
‘We have redesigned and revamped the boring old microscope to speed up cellular imaging, which will help researchers discover life-changing drugs more quickly and efficiently,’ concludes Orth.
Continuing this research, the team would like to expand to live cell imaging in which billion-pixel, time-lapse movies of cells moving and responding to various stimuli could be made, opening the door to experiments that currently aren’t possible with small-scale time-lapse movies.
