Sheath channel formation between capillaries for high throughput capillary electrophoresis

A cartridge, comprising:

• a first capillary configured for analyte separation during capillary electrophoresis;
• a second capillary configured to introduce reagents and analytes into the first capillary;
• a third capillary disposed between the first capillary and the second capillary, an inner diameter of the third capillary larger than an outer diameter of the first capillary and an outer diameter of the second capillary;
• and
• a waste tank disposed at at least one of a junction between the first capillary and the third capillary or a junction of the second capillary and the third capillary,
• the waste tank configured to contain an excess of a sample when a vacuum is applied to the second capillary via the waste tank to draw the sample from a sample reservoir and through the second capillary.

A method, comprising:

• applying vacuum to a second capillary via at least one of a junction of the second capillary and a third capillary or a junction of a first capillary and the third capillary while a first end of the second capillary is disposed in a sample reservoir, such that a sample is drawn from the sample reservoir into the second capillary,
• a first end of the first capillary inserted into a second end of the third capillary and a second end of the second capillary inserted into a first end of the third capillary such that the first end of the first capillary is in contact with the sample when the second capillary and the third capillary are filled with the sample, the first capillary configured for analyte separation during electrophoresis;
• disposing the first end of the second capillary into a run buffer reservoir after drawing the sample from the sample reservoir;
• applying vacuum to at least one of the junction of the second capillary and the third capillary or the junction of the first capillary and the third capillary while the first end of the second capillary is disposed in the run buffer reservoir such that a run buffer is drawn from the run buffer reservoir into the second capillary and the third capillary;
• and
• electrophoretically separating the sample in the first capillary.