High-peak-power 918-nm laser light source based two-photon spinning-disk microscopy for green fluorophores.

High-speed imaging of living specimen was performed using two-photon microscopy equipped with a spinning-disk scanning unit. Typically, a high-peak-power laser light source is needed to simultaneously induce two-photon excitation processes at several hundred focal points, generating the limitations of excitable fluorophores. Therefore, a high-peak-power neodymium-based 918-nm laser light source was used for intravital imaging of the most popular fluorophores, green fluorescent proteins. As a result, the proposed system obtained approximately 30 times brighter fluorescent signal than that obtained using a conventional mode-locked titanium:sapphire laser light source. Furthermore, the system visualized four-dimensional (xyz-t) calcium responses of pancreatic acinar cells agonist stimulations in the living G-CaMP7-expressing mouse with 60 million μm ³ volume.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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