This work presents the experimental investigation with electrokinetic flow mixing for bio-analytical chip applications. By DC electrokinetic instability induced technique, we design a 5x5 microfluidic device which possesses microfluidic sample handling in flow multi-switching. The device not only control single sample flows into different outlet considered but also the multi-sample injection into specific outlet ports. Experimental results indicate that the sample flow could be electrokintcally pre-focusing to a narrow stream and then guided into a desired outlet port and successfully control devices of the voltage in the microfluidic chip.