Calibrations were performed using
BCECF in seawater with pH 8.85 and pH 5.75 (Invitrogen Manual).
Ivy, "Detection of MRP functional activity: calcein AM but not
BCECF AM as a multidrug resistance-related protein (MRP1) substrate," Cytometry, vol.
As many bacteriocins are assumed to kill the target microorganism via permeabilization of the cell membrane [45], the effect of pentocin JL-1 on the membrane integrity of MRSA GIM 1.771 intact cells was determined by the membrane potential sensitive dye Dis[C.sub.2](5) (Figure 5) and the transmembrane pH gradient fluorescent probe
BCECF (Figure 6).
The fluorescence intensity of
BCECF is dependent upon the pH with a maximum response at an excitation of [lambda]=535 nm (F1), while at [lambda]=490 nm (F2), the intensity is independent of pH.
The total fluorescence intensity of
BCECF labelled YAC1 cells (Target-T) was determined after adding 1.0% Triton X-100 for lysing.
In this context, it is interesting to note that glutamate has previously been reported to promote an acidification of the internal milieu of catfish retinal horizontal cells as measured using the pH-indicator dye
BCECF [11].
Ratiometric imaging techniques using fluorescent pH indicator dyes such as
BCECF have begun to expand our knowledge of the control of pH within retinal neurons (cf 6, 7).