This paper describes the methodology and presents the findings from the testing of a prototype of the Berkeley microfabricated capillary array electrophoresis (MCAE) device, which is designed to provide fast, high-quality DNA separation because of its ability to create a nanoliter sample plug that requires only short separation distances and fast dissipation of Joule heating under high voltages.
The testing of the MCAE device in a forensic laboratory (The Virginia Department of Forensic Science) showed conclusively that this prototype has the capacity to meet the demands of commercial systems and thus be used in other environments. The MCAE device has great throughput potential; 96 short tandem repeat (STR) profiles can be separated in less than 30 minutes. Even when including the time for manual steps in the operation of the MCAE device, the speed and throughput potential should exceed that of the most widely used capillary array instruments. Future testing will incorporate all elements of the existing prototype system, as well as microchips with additional functions. Instrument performance was verified by PowerPlex 16 System profiling of single source, sensitivity series, mixture, and casework samples. Mock sexual assault samples were successfully analyzed using the PowerPlex Y System. Resolution was assessed by using the TH01, CSF1PO, TPOX, and Amelogenin loci. Resolution was comparable with commercial systems, as was the instrument’s precision. Successful replacement of the Hjerten capillary coating method with a dynamic coating polymer was performed. The descriptions of materials and methods addresses sample preparation, nonprobative samples, PCR amplification, separation and detection, instrument operation and data acquisition, data analysis for resolution and precision studies, the precision study, and the resolution study. 4 tables, 5 figures, and 40 references