Zip Tip Protocol for Peptide and Protein Analysis

Solutions

Stock solution:  1% TFA in dd H2O: 1ml dd H2O, 10 µL TFA 

Sample prep (0.1%~1.0% TFA in dd H2O):
    0.5% TFA in dd H2O: 500 µL 1% TFA/dd H2O, 500 µL dd H2O

Equilibration & Washing: (0.1% TFA in dd H2O):
    100 µL 1% TFA/dd H2O, 900 µL dd H2O

Wetting & Elution (50% ACN in 0.1% TFA):
    300 µL Acetonitrile, 300 µL 0.1% TFA in dd H2O

Procedure

NOTE: Resin bed provides back pressure, so set pipettor to 10 µL, depress plunger to dead stop and slowly release or dispense plunger throughout operation.

1) equilibrate:

• Aspirate 10 µL wetting solution into tip.
• Dispense to waste
• Repeat
• Aspirate equilibration solution
• Dispense to waste
• Repeat

2) bind & wash:

• Aspirate and dispense 3-7 cycles (simple mixtures), up to 10 cycles (complex)
• Aspirate washing solution
• Dispense to waste
• Repeat

3) elution:

• Dispense 1-4 µL of elution solution into clean vial (standard pipette tip) (note: if µ-C-18, dispense 0.5-2 µL of elution solution)
• Aspirate and dispense eluant through zip tip at least 3 times without introducing air. Sample recovery can be improved by increasing elution volume to 10 µL (but at expense of concentration)