Fig 1.
Representative spectral scan of lysed blood cells with increasing concentrations of sodium nitrite.
(A) 0 mM, (B) 6 mM, (C) 12 mM, (D) 15 mM, (E) 19 mM, (F) 25 mM, (G) 29 mM, (H) 58 mM, (I) 102 mM of sodium nitrite was added to blood aliquots, lysed, and added to 96 well plates in triplicate. Optical density was measured from 400 nm to 700 nm for each well. Arrows point to the hemoglobin peaks at 540 and 580 nm and a methemoglobin peak at 635 nm. Error bars correspond to the standard errors of the means.
Fig 2.
Methemoglobin levels in blood samples exposed to increasing concentrations of sodium nitrite.
(A) All species, (B) Avian blood samples, and (C) Mammalian blood samples. The data reported are the initial post KCN addition optical densities and represent the average of 3 (mammals), 4 (duck), or 9 (starlings) independent blood samples exposed to PBS or sodium nitrite. Error bars correspond to the standard errors of the means.
Fig 3.
Red color value variation with increasing methemoglobin levels.
Blood samples were treated with sodium nitrite or PBS, spotted onto Whatman filter paper, and scanned with a flatbed scanner. Scanned images were analyzed with ImageJ software to generate RCV, GCV, and BCV. The RCV data presented represents the average of 3 (mammal), 4 (duck), or 9 (starling) different scanned images and the error bars correspond to the standard errors of the means. GCV and BCV data represents an average of all 19 blood spot images from all species.
Table 1.
Comparative analysis of the spectrophotometric and colorimetric predicted percent methemoglobin levels.
Fig 4.
Percent methemoglobin color chart.
Predicted RCV generated from the starling, duck, and vole’s standard curve equations were averaged and used to generate custom color cards in MS Paint. Blue and green color values were estimated to be 40, which was based on the average blue and green color values in these samples.