Borealis Illuminator

One of the most dramatic differences that our spinning disk offers is an improvement evenness of illumination. The Diskovery Borealis illuminator excitation intensity varies by less 8% across the entire field. All other spinning disk systems sold use an unmodified Yokogawa head, and can experience variations of up to 20%. 
This can clearly have a dramatic impact on the accuracy of quantification. 
While it may be argued that corrections can be done in software, these field variations will shift between wavelengths and over time, making it very challenging to determine the correction required. 
Moreover, this irregularity in excitation intensity also means that there will be differential rates of bleaching across a sample, where less bleaching occurs at the edge of the field of view. Thus, over time, the apparent signal at the edge of the field of view may appear to increase relative to the signal at the center of the field of view. These artifacts cannot be accurately modeled with software correction.

Reduced sensitivity to laser wavelength and illumination artefacts

Figure 1 (left) shows the effect of laser wavelength on illumination profile in the CSU-X1 contrasting Borealis with the standard Yokogawa method. Standard CSU-X1 uniformity, measured by diagonal profile variation, can be > 40%, and throughput is typically 12-15%, while its excitation wavelength range is 400-650nm. The standard CSU-X1 has been improved above earlier models such as 10 and 22 and uses beam shaping with a single mode fibre.

In contrast, Borealis using multi-mode fibres and beam conditioning achieves uniformity of ≤5% and 20-25% throughput. Moreover, wavelength sensitivity is greatly reduced and laser coupling stability improved due to the larger core diameter of the fibre and its excitation wavelength range is extended to 400-750nm.

Improved flatness of illumination

Figure 2  (right) shows a 9 wide by 7 high field montage of mouse kidney section* with Alexa Fluor® 488 WGA, Alexa Fluor® 568 phalloidin, DAPI .

Captured with a 60x 1.4NA oil immersion objective on a Spectral Borealis system, using a 512x512 BT EMCCD camera, with MetaMorph Slide scan configured for image stitching with no overlap.

Even careful observation does not reveal joining boundaries!

* FluoCells® prepared slide #3

“ Before the upgrade, there was noticeable uneven image brightness across the field, which made quantitative image analysis difficult. Homogenous illumination by Borealis solved the illumination issue. In addition, homogenous illumination enables seamless stitching of multiple fields using a motorized XY stage.  ”
Masahiro Narimatsu, DDS, PhD, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital