Development of an Automated Sample Preparation Module for Environmental Monitoring of Biowarfare Agents

Abstract

An automated sample preparation module, based upon sequential injection analysis (SIA), has been developed for use within an autonomous pathogen detection system. The SIA system interfaced aerosol sampling with multiplexed microsphere immunoassay-flow cytometric detection. Metering and sequestering of microspheres using SIA was found to be reproducible and reliable, over 24-h periods of autonomous operation. Four inbuilt immunoassay controls showed excellent immunoassay and system stability over five days of unattended continuous operation. Titration curves for two biological warfare agents, Bacillus anthracis and Yersinia pestis, obtained using the automated SIA procedure were shown to be similar to those generated using a manual microtiter plate procedure.

Sequential Injection Immunoassay for Environmental Measurements

“…On the other hand, flow immunoassay systems for the sensitive detection of botulinum toxin were proposed based on a unique flow cell named a rotating rod flow cell. 40,41 Other SIA systems for monitoring aflatoxin B1 42 and biowarfare agents 43 have been reported.…”

Current and Developing Technologies for Monitoring Agents of Bioterrorism and Biowarfare

“…The signal intensity is proportional to the amount of target analyte in the sample. The xMAP technology has been incorporated into continuous environmental monitoring systems (123,196) and for detection of exposure to biothreat agents in humans (29,30).…”

Heightened sense for sensing: recent advances in pathogen immunoassay sensing platforms

“…plague and anthrax (it sounds like these are simulants) (Fig 2a). [16][17][18] In the presence of the target antigens, fluorescently-labeled reporter antibodies are able to complete the sandwich formation.…”

“…An example in which the Luminex® beads are used to enable an integrated and portable pathogen sensing instrument has recently been demonstrated in a system known as Autonomous Pathogen Detection System (APDS). [16][17][18][19] Subsequent improvements to the APDS system enabled rapid PCR genetic analysis of the antigen and wireless transmission of the obtained flow cytometry and PCR data to a remote/centralized location. 17,19 As illustrated in Fig 2b, the APDS system contains an aerosol collector to constantly "inhale" particles from its surrounding environment for analysis.…”

“…To achieve sample preconcentration in the aerosol collector, the APDS system uses a virtual impactor to capture 1-10 µM particles. [16][17][18] Another recent approach to pre-concentration includes the development of magnetic silica microparticles which, when coated with didecyldimethylammonium bromide, have been utilized by Yitzhaki and co-workers to efficiently capture and concentrate bacillus spores. 20 As few as 100 bacillus spores can be captured with 90% efficiency.…”