Abstract��
OBJECTIVE: To establish radioisotope (125I) tracer labelling methods for the determination of nerve growth factor (NGF) in mouse plasma. METHODS:125I��NGF was labelled with chloramine��T method, concentration of NGF in mouse plasma was determined by radioisotope tracer labelling method in conjunction with trichloroacetic acid (TCA) or SDS��PAGE, respectively, and the assay results of the two methods were compared. RESULTS: TCA method was used to measure the concentration of 50 mouse plasma samples compared with SDS��PAGE method. There was a good linear correlation (r=0.994 8) between the two methods. The lower limits of detection of the two methods for NGF in plasma were 2.0 ng��ml-1. Within��day and between��day coefficients of their variation were less than 10%. Their assay linearities were determined in the range of 12.5 ng��ml-1��400 ng��ml-1 in plasma (r=0.999 0 and r=0.999 7, respectively). The average recoveries of the two methods for NGF were 95.21% and 94.30%, respectively. CONCLUSION: Both the methods are constant, reliable and sensitive. They were complemental each other and are suitable for the determination of NGF concentration in mouse plasma.��
1998, Vol. 33 
