Skip to main content

Table 1 Buffers used in the Pseudo-Null Point pH determination experiment.

From: Cytosolic acidification as a signal mediating hyperosmotic stress responses in Dictyostelium discoideum

Buffer Composition Pseudo-Null pH
  (BA=butyric acid; TA=trimethyl amine)  
S1 3 mM BA/48 mM TA in SPB buffer, pH 7.0 7.6
S2 3 mM BA/12 mM TA in SPB buffer, pH 7.0 7.3
S3 3 mM BA/3 mM TA in SPB buffer, pH 7.0 7.0
S4 12 mM BA/3 mM TA in SPB buffer, pH 7.0 6.7
S5 48 mM BA/3 mM TA in SPB buffer, pH 7.0 6.3
S6 SPB buffer, pH 7.0 low osmolarity control
S1S S 1/400 mM sorbitol 7.6
S2S S2/400 mM sorbitol 7.3
S3S S3/400 mM sorbitol 7.0
S4S S4/400 mM sorbitol 6.7
S5S S5/400 mM sorbitol 6.3
S6S S6/400 mM sorbitol high osmolarity control
  1. Calibration of BCECF fluorescence emission ratios was performed according to the Pseudo-Null calibration method for human cell lines [25], with modifications for Dictyostelium cells. The Pseudo-Null pH values were calculated by the formula: pH Pseudo-Null = pHbuffer* log (c(Base)/c(Acid)).