Abstract

Steady-state spatially resolved diffuse reflectance spectroscopy is used to reconstruct absolute visible absorption spectra (λ = 450-610 nm) of tissue-simulating phantoms that contain intact mitochondria and red blood cells in physiologically relevant proportions. The spectra are analyzed to extract independent fitted concentrations of oxy- and deoxyhemoglobin and of oxidized and reduced mitochondria. The resulting hemoglobin oxygen-dissociation and mitochondrial oxidation-reduction curves exhibit <i>p</i>₅₀ parameters of 25 and 2.5 torr, respectively, in agreement with published values. These results demonstrate the potential for absolute quantitative cytochrome spectroscopy of tissue in the presence of hemoglobin in the visible wavelength region. Extension of these measurements to the <i>in vivo</i> case is discussed.

Measurement of the oxidation state of mitochondrial cytochrome c from the neocortex of the mammalian brain

Y. Sakata, M. Abajian, M. O. Ripple, and R. Springett
Biomed. Opt. Express 3(8) 1933-1946 (2012)

Transient absorption spectroscopy and imaging of redox in muscle mitochondria

Erkang Wang, Luke A. Whitcomb, Adam J. Chicco, and Jesse W. Wilson
Biomed. Opt. Express 13(4) 2103-2116 (2022)

Effect of pigment packaging on diffuse reflectance spectroscopy of samples containing red blood cells

Jarod C. Finlay and Thomas H. Foster
Opt. Lett. 29(9) 965-967 (2004)

Absorption and multiple scattering by suspensions of aligned red blood cells

V. S. Lee and L. Tarassenko
J. Opt. Soc. Am. A 8(7) 1135-1141 (1991)

Review of measurements and imaging of cytochrome-c-oxidase in humans using near-infrared spectroscopy: an update

Georgina Leadley, Topun Austin, and Gemma Bale
Biomed. Opt. Express 15(1) 162-184 (2024)