Injection method for microfluidic chips

A method for electrophoresis, the method comprising:

• forming an injection channel comprising a first end and configured to receive a sample through a sample well disposed on the first end of the separation channel;
• forming a separation channel comprising a first end and a second end;
• wherein the injection channel and the separation channel intersect to form a ‘T’ junction;
• disposing a first valve between a first end of the separation channel and the ‘T’ junction on the separation channel;
• disposing a second valve at the ‘T’ junction;
• wherein the second valve is a two-way valve;
• said valve being adapted to be positioned to either preclude flow between said first end of said separation channel and said second end of said separation channel or to preclude flow between said injection channel and said separation channel;
• loading a sample into said first end of said injection channel;
• opening said first valve and operating said second valve to preclude flow between said first end of said separation channel and said second end of said separation channel and using electrical potential to draw said sample into said first end of said separation channel;
• closing said first valve and operating said second valve to allow flow between said first end of said separation channel and said second end of said separation channel and to preclude flow between said injection channel and said separation channel;
• and
• injecting a portion of the sample into an area between the ‘T’ junction and a second end of the separation channel using an electrical potential between said first valve and said second end of said separation channel.