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Changes in Optical Properties of Human Whole Blood in vitro Due to Slow Heating
Author(s) -
Nilsson Annika M. K.,
Lucassen Gerald W.,
Verkruysse Wim,
AnderssonEngels Stefan,
Gemert Martin J. C.
Publication year - 1997
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1997.tb08572.x
Subject(s) - scattering , light scattering , temperature coefficient , absorption (acoustics) , materials science , whole blood , dynamic light scattering , chemistry , scattering coefficient , attenuation coefficient , integrating sphere , analytical chemistry (journal) , optics , molecular physics , chromatography , physics , nanotechnology , biology , composite material , nanoparticle , immunology
Optical properties of human whole blood were investigated in vitro at 633 nm using a double integrating sphere set‐up. The blood flow was maintained at a constant rate through a flow cell while continuously heating the blood at 0.2–1.lC/min from approximately 25 to 55°C in a heat exchanger. A small, but rather abrupt decrease in the scattering asymmetry factor (g‐factor) of 1.7 ± 0.6% and a similar increase in the scattering coefficient of 2.9 ± 0.6% were observed at approximately 45–46°C yielding an increase in the reduced scattering coefficient of 40 ± 10%. Furthermore, a continuous, manifest increase in the absorption coefficient was seen with increasing temperature, on average 80 ± 70% from 25 to 50°C. The effect of the heating on the blood cells was also studied under a white‐light transmission microscope. A sudden change in the shape of the red blood cells, from discshaped to spherical, was observed at approximately the same temperature at which the distinct changes in g‐factor and scattering coefficient were observed, i.e. at 45–46°C. The results indicate that this shape transformation could explain the sudden change in scattering properties.