Fahrbach, F.O. & Rohrbach, A. Nat. Commun. 3, 632 (2012).

The use of a light sheet to illuminate a sample for microscopy can speed up imaging and reduce light exposure to the sample. Sheet-based illumination typically uses a standard Gaussian beam with a single wide peak. Bessel beams, in contrast, have a very narrow central peak with a ring system of light surrounding it. The ring system gives Bessel beam light sheets a unique self-healing capacity and improves propagation in scattering media but degrades resolution. Fahrbach & Rohrbach demonstrate a simple way to avoid resolution degradation while retaining the self-healing capacity of Bessel beams. They show that use of confocal line detection to remove signal coming from ring-based excitation preserved the self-healing capability of the Bessel beam light sheet while removing the undesired out-of-focus light. They demonstrate a near-doubling of axial resolution when imaging fluorescent polystyrene spheres in agarose gel or fluorescently labeled fruit fly ovaries.