Development and evaluation of a chemiluminescence immunoassay for type Ⅰ procollagen N-terminal peptide / 生物工程学报

To develop a magnetic nanoparticle chemiluminescence immunoassay (CLIA) for the determination of type Ⅰ procollagen N-terminal peptide (PINP) in human serum, we expressed a recombinant PINP-α1 protein in Corynebacterium glutamicum and used it as an immunogen to immunize BALB/c mice. We obtained three hybridoma cell lines that stably secret antibody against PINP-α1 protein. After further pairing and screening, we chose a monoclonal antibody 8C12 coupled with biotin as the capture antibody, and a monoclonal antibody 1F11 labeled horseradish peroxidase as the detection antibody. The antibodies combined with the serum samples, forming a sandwich complex which was used to detect the concentration of PINP in serum. After optimizing the conditions, we determined that the best working concentration of the capture antibody and the detection antibody were 3 μg/mL, and the incubation time was 30 minutes. The quantitative assay had a detection range of 5-1 100 ng/mL, with recovery rates between 93%-107% and the minimum detection limit of 1.22 ng/mL achieved. The intra-and inter-assay precisions were lower than 10%. The correlation coefficient of PINP results between this CLIA method and the Roche electrochemiluminescence immunoassay system was 0.906 2. Therefore, this CLIA method is specific and can be used to quantitatively detect the content of PINP in serum, which has the potential to become an auxiliary approach for bone disease examination.

Simultaneous Determination of Phenolic and Salicylanilide Anthelmintics Multi-residues in Cattle and Ovine Tissues by HPLC-MS/MS / 分析化学

A high performance liquid chromatography-tandem mass spectrometric( HPLC-MS/MS) method was developed for the simultaneous determination of four phenolic and salicylanilide anthelmintics including nitroxinil, oxyclozanide, closantel and rafoxanide in cattle and ovine tissues. Muscle, liverand kidney were extracted with acetonitrile-acetone(60:40, V/V)and fat with 1% triethylamine in acetonitrile, then the extract was purified with MAX solid-phase extraction column. Qualitative and quantitative analysiswas achieved by HPLC-MS/MS undernegative multiple reaction monitoring ( MRM) mode. Good correlation coefficients were obtained (R>0. 99) in the concentration range of 1-100 μg/L. The limits of detection (LOD) and limits of qualification (LOQ) for the four compounds were 1 and 2. 5 μg/kg, respectively. The mean recoveries at the four levels of LOQ, 0. 5 maximum residue limit (MRL), MRL, 2MRL were between 71% and 112%,with the intra-day relative standard deviation(RSD)in the range of 1. 1%-14. 0%and inter-day RSD in the range of 6. 4%-14. 7%. Forty samples from the market were analyzed with the method, only two samples were found to show phenolic and salicylanilide anthelmintics residues.