A Versatile "Sample-in-Answer-Out" Microfluidic System for Combined Detection of Multi-Functional Forensic Human...

On-site forensic DNA analysis has been hampered by inadequate automation and the limited scope of genetic information profiling. Here, a modular fully integrated microfluidic system is presented paired with a portable trolley-case analyzer to enable truly automated, on-site forensic DNA profiling. The system consists of a disposable plastic chip for DNA extraction/amplification (DEA) and a universal glass capillary electrophoresis (CAE) chip. The sample-in-answer-out platform generates complete DNA profiling within 124 min without any manual intervention in field environments. The automated system is successfully validated to directly process six types of forensic samples. Modular microfluidic cartridge interfaces are designed to support parallel analyses, including human identification via short tandem repeats (STRs), ancestry inference using insertion/deletion polymorphism (InDels), and paternity testing based on Y-chromosomal STRs (Y-STRs) and single nucleotide polymorphisms (Y-SNPs). Validation demonstrated a sensitivity of 0.5 ng for 21-locus STR profiling, enabling non-expert users to obtain complete profiles with just 1 min of hands-on operation. The DIP38 ancestry panel exhibited complete concordance with self-reported ethnicities. Crucially, the system allows for simultaneous Y-STR/Y-SNP detection in outdoor settings, facilitating assignment of the O-M122 haplogroup (ISOGG 2023). The development of this microsystem offer a fully automated solution for rapid on-site forensic DNA detection.