where; y0 is the first ratiometric value, y1 is the last ratiometric value, n is the Hill coefficient, and k is the effective concentration of the transporter used to elicit 50% of the observed transport activity. Due to the incomplete chloride efflux (not reaching the equilibrated or total chloride concentration in the system after the vesicles were lysed), an EC50 derived using the regular Hill equation would be incorrect. This is because rather than calculating the transporter concentration, which elicits 50% chloride efflux, the regular Hill equation would still calculate the transporter concentration, which elicits 50% of the maximum (100%) transport.