The absorbance spectrum of hemoglobin (Hb) can be used to obtain information about its state or condition. This simple measurement has been used for research in widely varying fields.
Dr Tobias Pusterla
The team at Venomtech have released an Application Note with BMG LABTECH that discusses their work studying the effect of different snake venoms on mammalian hemoglobin. They found that the venom from different species of snake had varying effects on the absorbance spectrum of rabbit hemoglobin when measured at 0 hours and after 16 hours.
Venom taken from snakes in the Viperidae family had the strongest effect on the hemoglobin; at 0 hours the absorbance spectrum showed 2 peaks characteristic of oxyhemoglobin (HbO2). Following treatment, the spectrum shifted to indicate the presene in the sample of methemoglobin (oxidised hemoglobin) rather than oxyhemoglobin.
A similar technique has been used in a completely different field to investigate the use of hemoglobin spectra to determine the age, and so time of deposition, of bloodstains at a crime scene. Studies have looked at the shift in the wavelength of a characteristic peak in the hemoglobin absorbance spectrum of dried bloodstains left for differing periods of time. Comparing this to this to the time since deposition has shown that it is possible to determine this to within hours.
These studies illustrate two very different applications that one assay can be used for. The use of a plate reader to automate the measurement and data recording of both of these is useful to the researchers to speed up and increase the amount of data acquisition, but would be invaluable were either of these techniques to be used in an industrial environment, such as a forensic laboratory at a crime scene.