A variant of GFP sensitive to this value is often fused to VAMP to track synaptic vesicle transport. An instrument used to measure this value is governed by the Nikolsky-Eisenman equation, and Glassoe and Long suggested correcting this value by an additive factor of 0.4 in deuterated media. For compounds like TFMS and certain carboranes, this value is often supplanted by a function named for Hammett. Hydrion strips can be used to measure this quantity, though it is more accurately measured using an ion-selective glass electrode. More often, compounds like bromothymol blue and phenolphthalein are used to estimate this value from color changes. For 10 points, name this value which ranges from 0 to 14, which is found by taking the negative log base 10 of the hydrogen 
A variant of GFP sensitive to this value is often fused to VAMP to track synaptic vesicle transport. An instrument used to measure this value is governed by the Nikolsky-Eisenman equation, and Glassoe and Long suggested correcting this value by an additive factor of 0.4 in deuterated media. For compounds like TFMS and certain carboranes, this value is often supplanted by a function named for Hammett. Hydrion strips can be used to measure this quantity, though it is more accurately measured using an ion-selective glass electrode. More often, compounds like bromothymol blue and phenolphthalein are used to estimate this value from color changes. For 10 points, name this value which ranges from 0 to 14, which is found by taking the negative log base 10 of the hydrogen concentration of an aqueous solution.
A variant of GFP sensitive to this value is often fused to VAMP to track synaptic vesicle transport.
pH [or pOH until "hydrogen" is read; prompt on "acidity" or "basicity"]