Figure 4
(A) Blue native-polyacrylamide gel electrophoresis profile of LDH after silver staining following the freeze–thaw process repeated five times. The concentration of the LDH solution was 40 μg/mL. Lane 1 was for untreated LDH, Lanes 2, 3, and 4 were for freeze-thawed LDH treated at freezing rates of 0.2, 12.8, and 70.6 °C/min, respectively. The full-sized gel is presented in the supplemental information (Supplementary Fig. S2). (B) Intrinsic fluorescence emission spectra (300–420 nm) of 20 μg/mL LDH in 0.2 M Tris–HCl buffer (pH 7.4) after the freeze–thaw process was repeated five times. LDH solution was frozen at a freezing rate of 0.2, 12.8, or 70.6 ºC/min. The frozen samples were thawed in a water bath at 25 ºC for 5 min before analysis.
