Figure 2
19F NMR spectral time course of loading 5FBAPTA into RBCs in a suspension at 37 °C. The pink area highlights the resonance of free 5FBAPTA that was assigned a chemical shift δ = 0.0. Acquisition of the first spectrum started at 4 min after mixing 10 µL of 200 mM 5FBAPTA-AM in DMSO with the 0.5 mL RBC suspension of Ht = 0.65. NMR settings were as for Fig. 1. The inset shows the 5FBAPTA peak intensities (green dots) from each spectrum over the 99-min time course; the time indicated is at the centre of FID accumulation. The solid red line is an empirical quadratic fit to the data [(0.023 ± 0.001) t − (0.00013 ± 0.00001) t2] used to obtain the initial slope at t = 0, and to guide the eye. The errors bars are reciprocals of the S/N derived automatically using TopSpin 4.0.
