Zip-Tip purification
Reagents
(Use HPLC grade solvents, highest possible grade reagents and MilliQ water for all
preparations)

100% acetonitrile

50% acetonitrile / 0.1% Formic Acid

0.1% Formic Acid

Elution buffer : 75% acetonitrile / 1% Formic Acid
Procedure:
1.
Wetting and Equilibration
(Each washing step is preformed in a separate tube)
a. Activate a C18 Zip-Tip with 10μl of 100% acetonitrile for 2 times.
b. Wash 1 times with 10μl of 50% acetonitrile / 0.1% Formic Acid.
c. Equilibrate the tip with 10μl of 0.1% Formic Acid for 3 times.
2.
Sample binding
a. Draw 10μl of sample up and down in the Zip-Tip for 10 to 15 times, and
then discard the sample (or preserve in another tube).
b. Wash the tip with 10μl of 0.1% Formic Acid, and repeat 2b step.
3.
Elution
Elute the peptides twice with 5μl of Elution buffer.
The eluent is collected into a new tube.
4.
Regenerate
If the sample volume is greater than 10μl, the Zip-Tip is regenerated by flushing
10μl of 100% acetonitrile for 3 times, and then starts from step 1b.
5.
After Zip-Tip purification, the sample has to be lyophilized, and store at -20℃.