Aim To explore the feasibility of the micro- dynamic chromogenic method for quantitative detection of bacterial endotoxin in recombinant novel coronavirus vaccine ( CHO cell).Methods The micro-dynamic color method of Limulus reagent was used to establish a bacterial endotoxin standard curve.The dilution factor was determined through interference pre -experiment, the recoverv rate of the endotoxin added to the test so- J lution was determined, and the interference test to complete the quantitative detection test of the bacterial endotoxin content in the test product was performed, and the results were compared with those of the gel-clot method.Results Hie linear range of the concentration of the standard curve was 0.02 to 2.0 EU • mL 1 , and the regression equation of the standard curve was lgT =-0.302 7 lgC +2.858 7( r = 0.998 9).When recombinant novel coronavirus vaccine ( CHO cell) was cliluted 40 times or below, the micro -dynamic chromogenic reagent did not interfere with the bacterial endotoxin agglutination reaction, and the recovery rate was 50% to 200%.The test results were consistent with the gel- clot method.Conclusions The micro-dynamic chromogenic method can be used for the quantitative detection of bacterial endotoxins in recombinant novel coronavirus vaccine ( CHO cell) with accurate results, high sensitivity, and process monitoring.

Objective:To prepare 68Ga-2-(4, 7-bis(carboxymethyl)-1, 4, 7-triazonan-1-yl)pentanedioic acid (NODAGA)-YHWYGYTPQNVI (GE11) and evaluate its feasibility of PET imaging for pancreatic cancer. Methods:GE11 peptide was conjugated with NODAGA and then labeled with 68Ga. The labeling yield, radiochemical purity, hydrophilicity, stability and specificity in vitro were determined. Human pancreatic cancer BxPC3 nude mice models ( n=9) were established. MicroPET imaging was then obtained after 30 and 90 min, and mice were sacrificed at 90 min to acquire the radioactivity distribution of main organs and tumors. Pair t test was used to analyze the data. Results:The labeling yield was (73.5±5.4)% and radiochemical purity was more than 98%. After incubation 120 min in mouse serum at 37 ℃, radiochemical purity was more than 92%. The uptake was specific in BxPC3 cell lines. MicroPET images showed that 68Ga-NODAGA-GE11 could accumulate quickly in tumor. Value of tumor uptake was significantly higher than that of normal pancreas at 90 min ((1.38±0.25) vs (0.49±0.07) %ID/g; t=12.67, P<0.05), and the radio-uptake of blood, muscle and bone was lower than that of tumor. Conclusions:68Ga-NODAGA-GE11 is easy to be prepared with high radiochemical purity and good stability, and can specifically target BxPC3 xenograft tumor. However, due to the high uptake in the kidneys and liver, the value of 68Ga-NODAGA-GE11 in PET imaging for pancreatic tumor needs further study.

Objective: To establish a real-time fluorescence recombinase acid amplification (RAA) method for the detection of adenovirus type 3(HAdV-3)without extraction nucleic acid. Methods: According to the conserved sequence of adenovirus type 3 gene, a pair of primers and a probe were designed, and a real-time fluorescence RAA without extracting nucleic acid was established and optimizing the condition of DNA-free extraction. The sensitivity of the method was analyzed by a series of dilution and the specificity of the method was evaluated by detecting the original samples of other respiratory viruses. The clinical samples of HAdV-3 were detected and compared with the traditional real-time fluorescence quantitative PCR method for nucleic acid extraction. Results: The sensitivity of the real-time fluorescence RAA method was as high as that of qPCR in the detection of 10 series diluted HAdV-3 strains. The highest corresponding CT value of qPCR was 36.87. The sensitivity of the real-time fluorescence RAA method was similar to that of the real-time fluorescence quantitative PCR method . There was no cross-reaction to other common types of respiratory viruses. The two method were used to detect 56 clinical samples at the same time, and the result were completely consistent. Conclusions We provide the first report of the real-time fluorescent RAA assays for the detection of HAdV-3 without extracting nucleic acid and it has high sensitivity and specificity. Is suitable for rapid detection of HAdV-3 in clinical laboratories and on-site unite.