Biphasic Oxidation of Oxy-Hemoglobin in Bloodstains
Author Information
Author(s): Bremmer Rolf H., de Bruin Daniel M., de Joode Maarten, Buma Wybren Jan, van Leeuwen Ton G., Aalders Maurice C. G.
Primary Institution: Academic Medical Center, University of Amsterdam
Hypothesis
The study investigates the conversion rates of oxy-hemoglobin to met-hemoglobin and hemichrome in bloodstains and how these rates are affected by temperature and humidity.
Conclusion
The oxidation rate of oxy-hemoglobin in bloodstains is biphasic, being rapid initially and slowing down after a few hours, with rates strongly dependent on temperature but independent of humidity.
Supporting Evidence
- The oxidation of oxy-hemoglobin is rapid initially but slows down after a few hours.
- Oxidation rates are strongly dependent on temperature.
- The transition of met-hemoglobin to hemichrome is influenced by humidity.
- The study provides a method for estimating the age of bloodstains in forensic settings.
Takeaway
When bloodstains age, they change color because the hemoglobin in the blood turns into different forms, and this process happens quickly at first and then slows down, especially when it's warm.
Methodology
The study used quantitative analysis of optical reflectance spectra and Optical Coherence Tomography to measure the fractions of hemoglobin derivatives in bloodstains as a function of age, temperature, and humidity.
Limitations
The study's findings may not apply to bloodstains on non-white substrates without further analysis.
Participant Demographics
Blood was drawn from a healthy nonsmoking volunteer.
Statistical Information
Confidence Interval
95%
Digital Object Identifier (DOI)
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