Key Considerations for the use of ALZET pumps in vitro
Temperature
The pumping rate for ALZET pumps is temperature dependent. Nominal rates for each pump model assume 37°C. Note that temperatures above 42°C have been found to cause fluctuating delivery rates and are not recommended. Use the calculator below to predict the release rates of ALZET pumps at different temperatures.
Osmolality
Nominal pumping rates provided for ALZET pumps assume that the fluid surrounding their outer membrane is at normal mammalian osmolality (310 milliosmols/L) which is equivalent to an osmotic pressure of 7.5 atm. Note that these formulae are useful for osmotic pressures in the range of 0-25 atm. Use the calculator below to predict the release rates of ALZET pumps at different osmolalities.
Water Source
Proper operation of the ALZET pump requires that the outer membrane be completely surrounded by aqueous solution for the entire infusion period. For example, placing the pump in saline-filled test tubes suffices.