Patent ID: 6994778

Claim:
A microfluidic device for analyzing a sample, comprising: a base member; a separating channel formed in the base member; a sample injecting portion formed at one end of the separating channel; a sample quantity control channel formed in the base member and branching from the separating channel, said sample quantity control channel having a volume for the sample to be introduced from the sample injecting portion; a first opening and closing mechanism disposed at the other end of the separating channel, said first opening and closing mechanism being opened when a migration buffer is introduced into the separating channel, and then closed; and a second opening and closing mechanism disposed at one end of the sample quantity control channel away from the separating channel, said second opening and closing mechanism being closed when the migration buffer is introduced into the separating channel, and opened when the sample injecting portion is immersed into a sample so that the sample is introduced into the separating channel for the volume of the sample quantity control channel while the migration buffer in the separating channel enters the sample quantity control channel by capillary phenomenon.