| Abstrakt: |
A manual Mycobacterium avium subspecies paratuberculosis antibody enzyme linked immunosorbent assay (ELISA) (IDEXX Inc.) was fully automated using an automation workstation system (AWS). The IDEXX commercial kit is used to screen for exposure to the Johne's disease (JD) bacterium in cattle on a herd basis. Due to the large number of sera involved in this type of surveillance project, there is a need to increase the cost effectiveness and decrease the turn around time. The purpose of the work was to develop an automated ELISA (a-ELISA) for JD antibodies screening and examine the productivity advantages, quality assured performance characteristics, the laboratory information management (LIM) work, and the multitasking provisions under this format.The AWS was assembled using a modular approach design. The high-throughput screening configuration consisted of a Beckman Coulter hybrid Biomek FX liquid-handling system integrated with a Molecular Devices Spectramax microplate reader, a Biotek ELx405 microplate washer, a Kendro Cytomat 6000 hotel, and an Axis PTZ Network camera. The integrated system function was programmed with an IBM computer using the SAMI software. This setup was housed in a Class 2 Biosafety Cabinet. This fully automated system provided flexibility to accommodate the multistep requirements of the immunoassay procedure. Complexity of the working steps was kept to a minimum by using one unique operation program. The complete robotic workstation with its peripheral equipment was simple to operate, robust, and easily maintained. These characteristics enabled the elimination of forced downtime due to human and/or machine failure. A 5 to 10 fold improvement in cost, test capacity, and productivity was achieved. With this system, one diagnostician is able to carry out over 1000 antibody screening tests a day. Based on the automated nature of the test, there is ample walk away time between the ELISA tests, enabling the technologist to multitask--performing other important duties such as sample receiving and preparation, test validation, result interpretation, information dissemination, and other related LIM work.The performance characteristics--such as repeatability, reproducibility, optimal cutoff values, identity score, test sensitivity, and specificity were evaluated. These test validation results were based on data accumulated in an 8-year proficiency testing with the US National Veterinary Services Laboratory. Our laboratory test has received certification from the United States Department of Agriculture to perform serologic testing for JD since 1998. In 2000-2001, this test scope was accredited by the Standard Council of Canada. In 2004, this a-ELISA was validated according to the requirements of the ISO/IEC 17025 standard. [ABSTRACT FROM AUTHOR] |
