specific radioactivity
1.Oncomodulin (oncoM)──a mark of tumor was purified from human tumor tissues,and was labelled with high specific radioactivity by conjugating to an 125I-iodinisated acylating agent. The specific activity of 125I-oncoM was 0.20-0.34MBq/μg and its radiochemical purity was 96%.
2.The carbamyl phosphate synthetase I (CPS,) cDNA probe labelled with alpha ~(35)S-dATP was obtained by using modified nick translation technigue. The specific radioactivity of the obtained probe reached 0.9-1.5×10~8cpm/ug DNA.
3.Results The whole synthesis process took about 4 min from 11C-methyl iodide to 11C-β-CFT. The synthesis yield (end of bomardment) was (92.4±3.1)%, the radiochemical purity over 98%, and the specific radioactivity was more than 2 TBq/mmol.
4.By means of modified nick translation techique,probes with specific radioactivity of over 108 dpm/μgDNA labeled by alpha-35S-dATP were obtained,which can be satisfactorily used in Southern blot hybridization for detecting single copy genes in human genomic DNA,The advantages of using 35S instead of 32p were discussed.
5.Under the optimum conditions, the composite nano-particles of (110Agm) Ag/TiO2 were synthesized with radiochemical yield of 93.6% and specific volume radioactivity of 0.6MBq/mL.
6.The specific activity of 134Cs in fish flesh was low but the percentage of radioactivity was high that was about 30% of total raioactivity in the fish.
7.The results indicate that the radioactivity specific activity of Chinese zircon is higher one order of magnitude than that of Australian zircon which can meet the requirement of industrial application ;
