“…The most common heme centers in biological samples are heme A, heme B, and heme C, and these centers have α bands located at $605, $565, and $550 nm, respectively (Keilin, 1925). However, it should be noted that obtaining spectra in this way necessitates the use of more advanced spectrometers such as a photomultiplier tube to increase sensitivity ( Jones, 1985) or utilization of custom cuvettes to minimize path length in these turbid suspensions . Heme centers generate strong signals when the iron is in a reduced state, but the signal diminishes greatly when the iron is oxidized.…”