Isotachophoresis of blood-derived samples

A method for separating a complex, the method comprising:

• (1) introducing in a capillary, between a leading buffer zone and a trailing buffer zone, wherein neither the leading buffer nor the trailing buffer comprises an ion selected from a 2-(N-morpholino)ethane sulfonate ion and a glutamate ion:
• (a) a blood-derived sample suspected of containing an analyte, (b) a labeled analyte analog, and (c) one or more mobility-changing complex forming substances (CFS);
• (2) contacting the analyte, the labeled analyte analog, and the one or more mobility-changing CFSs, wherein a first complex comprising the labeled analyte analog and at least one of the one or more mobility-changing CFSs and a second complex comprising the analyte and at least of one of the one or more mobility-changing CFSs are formed;
• and
• (3) separating the first complex from the labeled analyte analog not part of said first complex and coexisting substances in the blood-derived sample by performing isotachophoresis in the presence of a 2-(N-morpholino)ethane sulfonate ion and/or a glutamate ion between the leading buffer zone and the trailing buffer zone.

A method for separating a complex, the method comprising:

• (1) arranging in a capillary, between a leading buffer zone and a trailing buffer zone, wherein neither the leading buffer nor the trailing buffer comprises an ion selected from a 2-(N-morpholino)ethane sulfonate ion and a glutamate ion:
• (a) three zones comprising (i) a solution of a blood-derived sample suspected of containing an analyte, (ii) a solution of one or more mobility-changing CFSs, and (iii) a solution of a labeled analyte analog, as separate zones;
• or
• (b) two zones comprising (i) a solution of a blood-derived sample suspected of containing an analyte and (ii) a solution of a labeled analyte analog and one or more mobility-changing CFSs, as separate zones;
• or
• (c) two zones comprising (i) a solution of a labeled analyte analog and (ii) a solution of a blood-derived sample suspected of containing an analyte and one or more mobility-changing CFSs, as separate zones;
• or
• (d) two zones comprising (i) a solution of a blood-derived sample suspected of containing an analyte and a labeled analyte analog and (ii) a solution of one or more mobility-changing CFSs, as separate zones;
• (2) contacting the blood-derived sample suspected of containing an analyte, the one or more mobility-changing CFSs, and the labeled analyte analog, wherein a first complex comprising the labeled analyte analog and at least one of the one or more mobility-changing CFSs, and a second complex comprising the analyte and at least one of the one or more mobility-changing CFSs are formed;
• (3) separating the first complex from the labeled analyte analog not part of said first complex and coexisting substances in the blood-derived sample by performing isotachophoresis in the presence of a 2-(N-morpholino)ethane sulfonate ion and/or a glutamate ion between the leading buffer zone and the trailing buffer zone;
• and
• (4) separating the first complex and coexisting substances in the blood-derived sample by performing capillary zone electrophoresis or capillary gel electrophoresis.

A method for separating a complex, the method comprising:

• (1) introducing in a capillary, between a leading buffer zone and a trailing buffer zone, wherein neither the leading buffer nor the trailing buffer comprises an ion selected from a 2-(N-morpholino)ethane sulfonate ion and a glutamate ion:
• (a) a blood-derived sample suspected of containing an analyte, (b) a mobility-changing analyte analog, and (c) one or more labeled complex forming substances (CFS);
• (2) contacting the analyte, the mobility-changing analyte analog, and the one or more labeled CFSs, wherein a first complex comprising the mobility-changing analyte analog and at least one of the one or more labeled CFSs and a second complex comprising the analyte and at least of one of the one or more labeled CFSs are formed;
• and
• (3) separating the first complex from the second complex, the labeled CFSs not part of said first complex or said second complex, and coexisting substances in the blood-derived sample by performing isotachophoresis in the presence of a 2-(N-morpholino)ethane sulfonate ion and/or a glutamate ion between the leading buffer zone and the trailing buffer zone.

A method for separating a complex, the method comprising:

• (1) arranging in a capillary, between a leading buffer zone and a trailing buffer zone, wherein neither the leading buffer nor the trailing buffer comprises an ion selected from a 2-(N-morpholino)ethane sulfonate ion and a glutamate ion:
• (a) two zones comprising (i) a solution of a blood-derived sample suspected of containing an analyte and (ii) a solution of a mobility-changing analyte analog and one or more labeled CFSs, as separate zones;
• or
• (b) two zones comprising (i) a solution of a mobility-changing analyte analog and (ii) a solution of a blood-derived sample suspected of containing an analyte and one or more labeled CFSs, as separate zones;
• (2) contacting the blood-derived sample suspected of containing an analyte, the one or more labeled CFSs, and the mobility-changing analyte analog, wherein a first complex comprising the mobility-changing analyte analog and at least one of the one or more labeled CFSs, and a second complex comprising the analyte and at least one of the one or more labeled CFSs are formed;
• (3) separating the first complex from the second complex, the labeled CFSs not part of said first complex or said second complex, and coexisting substances in the blood-derived sample by performing isotachophoresis in the presence of a 2-(N-morpholino)ethane sulfonate ion and/or a glutamate ion between the leading buffer zone and the trailing buffer zone;
• and
• (4) separating the first complex and coexisting substances in the blood-derived sample by performing capillary zone electrophoresis or capillary gel electrophoresis.