We demonstrate that both oxyhemoglobin and deoxyhemoglobin have sequential two-color, two-photon absorption properties that can serve as endogenous contrasts in microvasculature imaging. Using a sensitive modulation transfer technique, we are able to image hemoglobin in red blood cells with micrometer resolution, both in vitro and in vivo. We show that excellent contrast from hemoglobin without any labeling can be obtained in tissue.
© 2007 Optical Society of America
Original Manuscript: June 15, 2007
Revised Manuscript: July 26, 2007
Manuscript Accepted: August 1, 2007
Published: September 4, 2007
Vol. 2, Iss. 10 Virtual Journal for Biomedical Optics
Dan Fu, Tong Ye, Thomas E. Matthews, Benny J. Chen, Gunay Yurtserver, and Warren S. Warren, "High-resolution in vivo imaging of blood vessels without labeling," Opt. Lett. 32, 2641-2643 (2007)