Biosensors Hardware Test Report

MSD Cartridge Reader Overview The Meso Scale DiscoveryÂŽ Point of Care Cartridge Reader uses Multi-ArrayÂŽ electrochemiluminescence (ECL) technology to provide highly-sensitive multiplexed detection in a small volume of liquid sample. The instrument carries out measurements using single-use injection-molded fluidic cartridges customized with existing JPEO-CBMS Critical Reagents Program antibody pairs. Multiplexed measurements of integrated fluidics on-board the cartridge allow for fully automated sample processing and analysis of up to 20 targets in a single sample.

The Cartridge Reader was tested to evaluate the technology and verify vendor claims of limits of detection (LOD) for five biothreat agents (two bacterial, two viral, and one protein neurotoxin).

The Cartridge scanner is a simple to use device that processes cassettes containing assays for each target using microfluidics. A user pipets 165ÂľL of sample into the sample port, caps the port, and inserts the cassette into the device. Results are available in approximately 30 minutes and are displayed on the device screen as Positive or Negative. The customized cartridges contained assays for all 5 targets studied in this evaluation split between two channels within the cassette. Each channel contains a negative and a positive control for quality control. There is space for a total of 6 assays plus a positive and negative control on each channel; therefore, a cassette could be developed to test for 12 targets simultaneously.

The LODs reported for each target were taken from the results of Joint Biologcial Tactical Detection System (JBTDS) Technical Readiness Evaluation (TRE) 09-1 and are the lowest concentration which yielded 100% detection of the agent. The LOD of the BoNT A assay is from work funded by the NIH/NIAID and is for agent in buffer.

Data Bacillus anthracis Gram positive, spore forming bacilli Gamma-irradiated B. anthracis was diluted serially in 10-fold increments into water and tested based on the flow chart in Figure 1 beginning with the most concentrated sample and progressing toward the most dilute sample until a negative result was obtained. Because the 1.00x104 CFU/mL sample was negative, 1.00x105 CFU/mL was tested in triplicate. All three samples were detected positive; therefore, the LOD of the device was determined to be 1.00x105 CFU/mL which is in agreement with the JBTDS TRE data supplied by the vendor.