Article Abstract:
Protective antigen (PA) was generated from a recombinant, asporogenic, nontoxigenic and nonencapsulated host strain of Bacillus anthracis and the protein product was purified and characterized. About 20 to 30 mg of secreted PA per liter was produced from fermentation. Under these fermentation conditions, secreted protease activity was low and was inhibited by more than 95% by EDTA. Diafiltration and anion-exchange chromatography achieved a purity of 83% to 93%, while additional hydrophobic interaction chromatography achieved a final purity of more than 95%.
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Article Abstract:
The immunomagnetic electrochemiluminescence (IM-ECL) is highly sensitive to Sterne strain spores in phosphate-buffered saline. The lower detection limits for the other two strains of Bacillus anthracis, Ames and Vollum 1B, is much higher than for the Stern strain, suggesting the strain-dependent detection of IM-ECL. The strain-dependent detection limits of IM-ECL in buffer is in the range of ten squared to ten to the power five spores. IM-ECL exhibits a rank order of sensitivity for the assay in buffer which is Sterne > Ames > Vollum 1B.
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Article Abstract:
A commercial sensor method using immunomagnetic separation and electrochemiluminescene (ECL) detects 1,000 to 2,000 Escherichia coli O157 and Salmonella typhimurium cells per ml of food and environmental samples. The method has a low processing and assay time. The background noise and number of wash steps required is less. The method is more effective than ECL alone in dense samples and after short-term preenrichment of the samples. However, the test is not entirely specific for the target enteric pathogenic bacteria.
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