RESUMEN
The anhydrite and gypsum are the main sulfate minerals during evaporation of seawater or lake.They record the information about relative hydrogeology and the composition of mother liquor.Boron is diffluent element, and often occurs in all kinds of evaporites.Presently, the boron isotope has been applied widely in mineral deposits forming, geochemistry and palaeoenvironment.However, there is little research about characteristic of boron isotope in anhydrite and gypsum minerals, because of the low content of boron and micro-solubility in water and hydrochloric acid.This study developed a method of extracting and purifying boron in anhydrite and gypsum by phase transformation and ion-exchange.Firstly, the samples were mixed with ammonium hydrogen carbonate to transform the calcium sulfate to calcium carbonate.And diluted hydrochloric acid (1 mol/L) was added to resolve calcium carbonate.The percent conversion was about 85%in the first stage, and up to complete resolution by repeating this process.Secondly, boron specific ion-exchange resin ( Amberlite IRA 743 ) was used to gather the boron ions fully and further refined the samples with more than 1 μg of boron by anionic and cationic resin mixed by Ion Exchange Ⅱ and Dowex 50 W × 8.Finally, according to the modified method by He, the values of boron isotope were determined by TIMS.The boron content is analytically pure gypsum was 3.501 ± 0.128 μg/g ( n=12 , RSD=3.6%) and the average recovery was 100.47%.Besides, the δ11B value of analytically pure gypsum added with NIST SRM 951 was 17.98‰±0.21‰ (n=3, RSD=1.2%).This method has good repeatability and can meet the requirements of boron isotopic measurement of anhydrite and gypsum.
RESUMEN
This study was aimed to develop a sandwich ELISA kit for the diagnosis of bovine tuberculosis.And it was applied and evaluated in the quarantine of bovine tuberculosis.We established a bovine IFN-γ release method in vitro and developing three batches of kits.The sensitivity,repeatability and retention period of the kit were all evaluated.Totally 961 serum samples were tested using the developed sandwich ELISA kit tuberculin skin test and a commercial ELISA kit.Our results showed that the detection limit of this ELISA was 8.21 mg/mL.The repeatability tests showed good reproducibility in the intraassay and inter-assay.At the same time,the retention period of the kit was more than 12 months.Compared with the tuberculin skin test,the positive coincidence rate was 70.59％ and the negative coincidence rate was 99.20％,while the total coincidence rate was 98.44％.And compared with the BOVIGAMTM kit,the positive coincidence rate was 91.30％ and the negative coincidence rate was 99.78％,while the total coincidence rate reached 99.58％.At the same time,the sensitivity and specificity of the sandwich kit were 85.00％ and 100％,respectively.We established a bovine IFN-γ release method in vitro and developing corresponding kits successfully have a good application prospect.
RESUMEN
We established an ELISPOT for bovine interferon-gamma (BoIFN-γ), and applied it in the diagnosis of bovine tuberculosis (bTB). Monoclonal antibodies that can bind with native BoIFN-γ were screened as the coating antibody and detecting antibody. After optimization of detecting conditions including coating antibody concentration, cell number, and detecting antibody concentration, the ELISPOT assay was established. Peripheral mononuclear cells (PBMCs) isolated from 30 cows were co-cultured with PPD, and detected with the ELISPOT assay. The optimal conditions of ELISPOT assay were 2.5 μg/mL coating antibody 2G5, 2.5 x 10(5) cells/well, and 1 μg/mL detecting antibody Bio-5E11. In these 30 cows tested both with the ELISPOT assay and the BOVIGAM kit, 11 cows were proved to be positive in ELISOPT assay with the sensitivity of 78.6%, and 12 cows were proved to be negative in ELISOPT assay with the specificity of 75%. The ELISPOT assay for BoIFN-γ could be used to detect bTB efficiently and it might be an alternative method for the diagnosis of bTB.