04/07 .2024

What is two-photon microscopy

Two-photon microscopy, also known as two-photon excitation (2PE) microscopy, is a fluorescence imaging technique that allows for the observation of living tissues up to a depth of about one millimeter. In the two-photon excitation model, a molecule simultaneously absorbs two photons whose individual energy is only half of the energy needed to excite that molecule, and then releases the energy to a fluorescence photon. Two-photon microscopy (TPM) generally uses a near infrared excitation wavelength laser that reduces the tissue autofluorescence and optical scattering. It offers a powerful tool for observing the intricate processes within living organisms, especially for studying the dynamics of neurons, neural circuits, and other cellular interactions in deep tissues.