Fabrication of a Microchip for efficient DNA Capture and Release from Human Blood Sample for Forensic Application

Here, a simple and low-cost polymer, poly methyl methacrylate (PMMA) based microchip was fabricated using a compression moulding press for efficient capture and release of DNA from low quantity of human blood sample. Surface functionalization of the microchip was carried out using UV/O3 plasma coupled with 3-amino propyl tri ethoxy silane (APTES) treatment. Chemical composition of amine functionalized microchip was identified using FT-IR and qualitative detection of surface amine groups was done using confocal microscope. Within this microchip, DNA was extracted using alkaline extraction in a time frame of less than 8 minutes from 2 μL of human blood. Further, the DNA yield in the elute was optimized using different DNA elution conditions, such as temperature and pH to obtain the maximum DNA release from the microchip. Fabricated microchips have a high DNA capturing capability as the maximum amount of DNA obtained in the eluent was 0.4ng/μL. The amount of DNA recovered in the elute increased depending on temperature and pH changes. The STR profile generated using DNA elute was comparable with STR profile generated with DNA captured on the microchip. In conclusion, this microchip can become the ideal platform for fast, low cost, efficient on-chip DNA extraction from trace forensic samples recovered from the crime scene.