The bioactivity assay of PEG-TA1, Tyr-PEG-TA1 and 125 I -Tyr-PEG-TA1 were performed by an enzyme immunoassay (EIA) method.

• 利用酶免疫分析(EIA)方法鉴定PEG-TA1增加酪氨酸残基前后以及Tyr-PEG-TA1经125I标记前后免疫学活性的变化。