Fluorescence imaging, compared to other modalities (eg. bioluminescence, MRI or nuclear imaging) is limited by the depth of penetration of photons in tissue, even in the near infrared part of the spectrum. Imaging in the second biological second window, also called NIR-II, between 900 nm and 1700 nm, brings a significant improvement regarding the depth at which signals can be detected and the resolution of resulting images. Also, it becomes possible to consider imaging through thin bone structures, like mouse skulls.
With the same philosophy we had developed our first imaging system for Near Infrared (NIR) fluorescence, Kaer Labs now also proposes its stand alone Open Fluorescence In Vivo Imaging System for NIR-II. The system benefits from the same flexibility and user friendliness as the original KIS for NIR-I but will help designers of new fluorescent agents to push further the limits of In Vivo Fluorescence imaging.
The system is designed for preclinical research only and should not be used for clinical use
Read the article about NIR-II fluorescence imaging at the Small Animal Optical Imaging Laboratory (LIOPA, Paris)
Different names for the same technique
The second biological window corresponds to the spectrum comprised between 900 nm and 1 700 nm. It is also referred to as the "near infrared 2", or NIR-II, region. It requires the use of InGaAs cameras, which are called SWIR cameras by their manufacturers, SWIR standing for Short Wave Infrared.
Imaging in the second biological window, NIR-II imaging and SWIR imaing are therefore three different phrases that refer to the same technique.
Vascularisation imaging in a mouse after injection of nanoparticles
Excitation: 808 nm and / or 980 nm
Collection: 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500nm (high pass filters)
Excitation type: laser
Field of view: 6.4 x 6.4 cm2
Image size (pixels): 1024 x 1024
Number of bits: 16
Image format: TIFF
Export format: AVI
Optical head - hand held or fixed on a stand
Can be controlled by a laptop
High power due to limited working distance
Dedicated filters to maximize sensitivity for a given wavelength (no filter wheel)
Near infrared fluorescence for better tissue propagation
Background recording and subtraction from fluorescence signal in real time
Pseudo colors and overlay in real time for easier image interpretation
Linear detection for quantification of the signal
High dynamic range of the detector, for quantification of weak and strong signals
On the fly quantification of ROI: histograms and signal kinetics
Tif image format recording for post acquisition quantification
Very easy to install and use
Only one parameter to adjust to optimize image quality and sensitivity
No proprietary image format, post acquisition analysis is possible with any scientific image processing software