| Monoclonal antibody techniques are very important tools in modern life science research. As biotechnology has developed so rapidly during recent years, the clinical application of monoclonal antibody in the treatment and diagnoses of cancer has achieved great success. Monoclonal antibody techniques would provide a promising way for the tumor diagnoses and treatment.1 Withdrawing the protein from the cells BIU-87,E-J and LOVO cells were incubated in RPMI 1640 that contains 10% fetal bovine serum(FBS).When the cells were about 80% confluent, Withdrawed the protein of three kinds cells then used for the following procedures.2 Production and purification of monoclonal antibody BDI-1 The mice was injected hybridoma BDI-1 in peritoneal cavity. After 10 to 14 days we harvested ascites including BDI-1 then use Protein G-agaros affinity chromatography rarefied ascites that had been got. So we gained antihuman bladder carcinoma monoclonal antibody BDI-1.3 Characterization of BDI-1Monoclonal antibody was identified by ELISA , indirect immunofluoresence, SDS-PAGE electrophoresis and dot blot. The results showed that the molecular weight of monoclonal antibody was 150KD, moreover, was composed by two light chains(25KD) and two heavy chains(50KD).It could specially united with the protein of person bladder cancer cell(BIU-87 and E-J)and not united with the protein of rectal cancer cell(LOVO). The titer of monoclonal antibody that we had gotten was 106.4 Animal model establishmentTumors were grown in 40 male BALB/C nu/nu mice that were 4 or 5-week-old by subcutaneous inoculation of 5×106/100ul E-J cells under the back skin. Till the tumor was approximately 1.0 cm3 in size, then animals were stochastically divided into 8 groups,then used for radioimmunoimaging.5 Synthesis of tracer 99mTc-BDI-1(99mTc- immune globulin) and quality controlWe selected method which the stannous chloride returnsd to original state to preparation 99mTc-BDI-1 and 99mTc- immune globulin. The two kinds of solution were both colorless and transparent,and had no the precipitation or the suspended particle with pH 7.0. The radiochemical purity of 99mTc-BDI-1 and 99mTc- immune globulin were higher than 90%.The radiochemical purity had no difference(p>0.05).6 SPECT imaging in nude mice6.1 SPECT imaging with 99mTc-BDI-1 in nude mice Four groups mice (20 mice) with subcutaneous xenografts were injected via tail vein with 11.1MBq of 99mTc-BDI-1 synthesized as described previously. Four groups mice were placed in a supine position at the center of vision, and imaging of static state were performed separately using SPECT scanner at 0.5 , 6 , 12 , 24 hour after injection.We collected data 30 minutes and calculate the T/N values of tumors on the imaging. At the end of imaging, all the mice were sacrificed and the main organs and tumors were excised and weighed. Not only activity of tissue samples were measured with Well-type Gamma Counter but also decay of tissue samples was corrected. Computed radioactivity uptake that was expressed as the %ID/g of tissue and T/NT values.6.2 SPECT imaging with 99mTc- immune globulin in nude mice Other four groups mice (20 mice) with subcutaneous xenografts were injected via tail vein with 11.1MBq of 99mTc- immune globulin synthesized as described previously. Four groups mice were placed in a supine position at the center of vision, and imaging of static state were performed separately using SPECT scanner at 0.5, 6 , 12 ,24 hour after injection.We collected data 30 minutes and calculate the T/Nvalues of tumors on the imaging. At the end of imaging, all the mice were sacrificed and the main organs and tumors were excised and weighed. Not only activity of tissue samples were measured with Well-type Gamma Counter but also decay of tissue samples was corrected. Computed radioactivity uptake that was expressed as the %ID/g of tissue and T/NT values.The result of imaging indicated that the uptake of 99mTc-BDI-1 in the urinary bladder cancer tissue was obviously higher than 99mTc- immune globulin. The %ID/g of 99mTc-BDI-1 and 99mTc- immune globulin in tumor at o.5h , 6h , 12h , 24h was respectively 0.67±0.19 and 0.035±0.01,1.49±0.33 and 0.053±0.02,4.97±1.21 and 0.16±0.12 ,22.7±8.25 and 0.33±0.12. Along with time passing, the %ID/g in tissues and organs(except brain ) was slowly increase,yet the %ID/g in tumor was rapidly increase and T/NT values increased.It was considered that 99mTc-BDI-1 could enter the tumor through blood pipe wall r,and retain specifical localization function of antibody.So the %ID/g of 99mTc-BDI-1in tumor increase obviously.The %ID/g of 99mTc-BDI-1 in the brain was few and changes with time was not obvious because 99mTc-BDI-1 couldn't cross blood-brain barrier. The organ of highest activity was kidney at each time. It was indicated that the tracer of 99mTc-BDI-1 mainly excreted by urinary tract. After injecting 99mTc- immune globulin, the %ID/g in neither tumor nor nontarget tissues/organs had obviously change. The activity of brain was lowest and kidney was highest because that 99mTc- immune globulin couldnot pass blood-brain barrier and excreted through urinary tract. That the activity of tumor was low indicated that 99mTc- immune globulin had no specifical localization function.
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