Japanese scientists have recently invented a microscope imaging solution that increases the accuracy of observing cells up to seven times that of existing techniques, based on existing optical microscope hardware and without the need for additional fluorogenic dyes, helping to observe viral activity inside and outside the cell in real time.
Cells are mostly translucent, and the basic principle of light microscopy is to image cells by detecting the subtle differences in light passing through different areas of the cell, also called phase differences, and then using a computer to convert the phase differences into changes in magnitude or contrast in the image. The imaging sensitivity of the microscope is therefore limited by the range in which the camera can detect the phase difference.
Takuro Ideguchi of the Institute of Photonic Science and Technology at the University of Tokyo says, “With the same imaging sensor, to see more detail, you need to widen the phase difference range to detect finer phase changes of light.”
But they invented a technique to obtain a more detailed image by exposing twice and imaging twice. Their new invention was recently published in the photonics journal Light: Science& Applications.
“Our method does not require a special laser, a special microscope or an image sensor. We are able to image living cells without the use of stains or fluorophores and without optically poisoning the cells.” Takuro Iguchi described.
The technique first images the cells in a conventional manner, after which the computer quickly designs a mirror light waveform in accordance with the image of the sample, and uses an additional meta to emit this mirror waveform for a second exposure and imaging of the cell sample.
The study says that if the first imaging is perfect, then the second time will yield a picture that is pitch black and empty. Of course this is not possible, so the second imaging can see some subtle phase differences.
The researchers then used computer analysis from the second subtle phase differences to combine the two photos and build a final image of the cell. This study shows experiments in which the researchers estimate that the new method of imaging is up to seven times more sensitive than existing techniques.
The advantage of this technique is that the activity of tiny particles inside living cells can be seen without any stains or fluorophores, said Takuro Iguchi.
“For example, nanoscale sized particles like viruses can be detected, moving inside and outside the cell, helping researchers to observe the activity of cells under the influence of viruses in real time.”
Recent Comments