Skip to main content
. 2018 Dec 15;10(12):539. doi: 10.3390/toxins10120539

Figure 2.

Figure 2

Time- and concentration-dependent changes in absorbance for MetHb over 16 h. Ovine Hb was incubated with a control (PBS) (A) or N. nigricollis venom (10 mg/mL to achieve maximum MetHb production) (B) at 37 °C in a plate reader (PHERAStar, BMG Labtech). The absorbance between 400 nm and 700 nm was measured every 2 h. The peaks typical of oxygenated Hb are at 540 nm and 570 nm, and those of MetHb are at 500 nm and 630 nm. Furthermore, the N. nigricollis venom was serially diluted from 1 mg/mL to 0.007 mg/mL and mixed with an equal volume of ovine Hb. It was then incubated for 16 h at 37 °C in a plate reader (FLUOStar Optima, BMG Labtech) and the absorbance was measured every 2 h at 500 nm (C) and 630 nm (D). The traces shown are representative of three separate experiments, and they were selected to clearly demonstrate the changes in absorbance for Hb and MetHb over a period of 16 h.