A new type of fluorescent nano-bead is presented by GATTAquant. These beads, called GATTA-Beads, are characterized by a small diameter (23 nm), high intensity and size uniformity. In combination with state-of-the-art STED microscopes such as the Leica TCS SP8 STED 3X and high-end image restoration methods available in the Huygens Software, it is shown that these new nano-beads can be used for accurate STED PSF characterization in 3D.

Furthermore, it is shown that the measured 3D STED-PSF can be used to improve image restoration quality in combination with STED deconvolution methods available in the Huygens Software.

Source: http://www.leica-microsystems.com/science-lab/measuring-the-3d-sted-psf-with-a-new-type-of-fluorescent-beads/