ALB and ischemia: During ischemia, a metabolic switch to increase lactate production causes a decrease in tissue pH.[19] With the decrease in pH levels from 7.19 to 3.38, the characteristic spectra of HSA binding IR‐780 complexes shifted to that of free IR‐780 beginning at low pH levels (≈6.23) (Figure 2E), suggesting that heart ischemic acidic microenvironment benefits from its specific release.