Last week, Confocal.nl signed the Eurostars project “DETECtORS” and will lead the multinational research and development team to build the first commercial near-infrared confocal microscope (RCM-NIR). Here we explain in detail, how will this project contribute to the fields neuroscience and cancer research.
The light of the confocal microscope can normally penetrate around 300 um into the tissue. This is determined by the physical properties of the tissue (scattering), but also by the wavelength of the light. Longer wavelengths penetrate deeper than shorter ones. In order to penetrate even deeper into the tissue, multi-photon (MP) microscopy was developed. The first MP confocal microscope was invented almost 20 years ago. In MP imaging, two IR photons come together in the focus plane and act like a photon with double the energy (half of the wavelength). Because of the longer wavelength the tissue can be penetrated deeper. Because the reduction (half) of the wavelengths in MP imaging, same visible range dyes can be used as in regular confocal microscopy. The drawback of MP confocal microscopy is the fact that very powerful lasers need to be used (3-5 Watt). These lasers are safety class 4 lasers, which means they can only be operated by trained staff in well shielded environments. With MP imaging, penetration depths of 1000 um = 1mm can be achieved, which can further be extended to about 5 – 10 mm by clearing the tissue.
Long wavelengths penetrate deeper than shorter ones. Because of this fact, the whole animal (mostly mouse) imaging systems are using (Near) Infra Red (NIR / IR) wavelengths. These whole animal imaging systems are used for molecular imaging. Molecular imaging originated from the field of radio pharmacology due to the need to better understand fundamental molecular pathways inside organisms in a noninvasive manner. As these systems need to image the whole animal, a macro camera is used. The disadvantage of the macro camera is that the resolution is rather low. Only the location of the target within the animal can be viewed, not the content.
The RCM-NIR using Single-Photon (SP) NIR / IR will greatly improve the resolution. It will not be able to scan the whole animal, but the target parts can now be investigated at much higher detail compared to the whole animal imaging systems. Because of the RCM technology, the lower resolution of IR wavelengths compared to the visible light, can be offset. 1,000 nm wavelength results in RCM-NIR resolution of 370nm, which is the same as 700nm regular confocal resolution.
The aim with this project is to provide new tools for neuro- and cancer research studies that allow them to see more tissue with higher detail, with the equipment that costs significantly less than any current option, which in turn allows more researchers to join the studies. Neuroscience will get a new tool that performs equally to the current MP system, but with less damaging and complicated lasers. Cancer research will get a new tool that allows the use of the same dyes as in whole animal studies, but at much higher resolution that exceeds even the standard confocal microscope.
For more details of the RCM system including working principle, specifications, application images, and system pictures, please refer to our website: https://saneasia.com/solutions/confocal/rescan-confocal/