Abstract: Objective To investigate the effect of centrifugal speed and temperature on urine proteome after acetone precipitation and the individual variation of urine proteome in normal people. Methods Human urine samples precipitated by acetone were centrifuged at different centrifugation speeds (4 000×g and 12 000×g) and temperatures (4 ℃ and 20 ℃). Urine proteins were extracted for mass spectrum analysis. The identification results of different methods were compared to determine the best conditions of urine protein centrifugation after acetone precipitation. The above methods were used to analyze the urine proteome of 36 normal people (male∶female =1∶1). Results Under the condition of low temperature and high speed (4 ℃,12 000×g), the identification effect was the best and the individual variation of the normal urine proteome was 0.635. Conclusions After acetone precipitation, the extraction effect of urine protein at low temperature and high speed (4 ℃, 12 000×g) is good. The individual variation of urine protein is similar to that of plasma proteome, which can be used for large-scale clinical analysis because of stability.

Key words: centrifugal temperature and speed, urine proteomics, individual variation