1. A method for multiple-sample DNA analysis, comprising: injecting a first template DNA extracted based on a first sample from a first well on a cartridge through a first inlet to a first reaction reservoir in a first domain of a microfluidic chip on the cartridge; injecting a second template DNA extracted based on a second sample from a second well on the cartridge through a second inlet to a second reaction reservoir in the first domain of the microfluidic chip, the second well being separate from the first well; inducing thermal cycles in the first domain of the microfluidic chip for PCR amplification of DNA fragments, the first domain including at least the first reaction reservoir designated for PCR amplification based on the first sample, and the second reaction reservoir designated for PCR amplification based on the second sample; inducing liquid flow to respectively move first amplified DNA fragments from the first reaction reservoir to a first separation unit in a second domain of the microfluidic chip, and second amplified DNA fragments from the second reaction reservoir to a second separation unit in the second domain of the microfluidic chip; inducing electric fields in the first separation unit to separate the first amplified DNA fragments by size in a first separation channel on the microfluidic chip; inducing electric fields in the second separation unit to separate the second amplified DNA fragments by size in a second separation channel on the microfluidic chip, the second separation channel being fluidically separated from the first separation channel; and detecting the separated DNA fragments.