Donor kidney viability test for improved preservation

A method for monitoring and determining the functional viability of a donor kidney prior to transplantation comprising:

• continuously, vascularly perfusing said kidney at about 7.degree. to about 10.degree. C. with a perfusate comprising a glomerular impermeable colloid, wherein the concentration of the colloid is about 0.1 to 4 gram percent of the perfusate, wherein kidney resistance determines the flow rate, wherein the perfusion pressure is no lower than 5 mmHg and the perfusion pressure is further correlated to the colloid concentration in a ratio of about 1 gram percent per 10 mmHg which prevents kidney tubule reabsorption of water and permits glomerular filtration of said perfusate and, determining the glomerular filtration rate of said kidney, which is equal to the urine output rate wherein an increase in the glomerular filtration rate is indicative of functional viability an a decrease in a glomerular filtration rate is indicative of functional deterioration.