MALDI-TOF Protein Prep

Mass spectrometry is a commonly identification method for the products of a protein digest, modification, purification, or the like. Sample preparation is handled via Ziptips, an extremely fast (if not expensive) method of reducing contaminants in your sample.

ZipTipping solutions

A. 0.2% TFA in HPLC grade water; for dilution of protein digests.

B. 0.1% TFA in 50% ACN/50% water; for peptide elution.

C. 100% acetonitrile (ACN); wetting agent for ZipTip.

D. 0.1% TFA in water; for equilibration of ZipTip

  1. For each unknown, label a 0.65 ml tube as a diluted sample. Combine 6.0 µl of solution A and 4.0 µl of your protein sample. Gently mix, and then cap the tube.

  2. Transfer 2.5 µl of solution B to the bottom of the tubes and cap them. Label as elution tubes

  3. Attach a ZipTip to your pipettor and set volume to 8 µl. Draw up 8 µl of solution C and dispense onto a Kimwipe. Keep the plunger down, and repeat once. Proceed to step #4 without letting the plunger retract, i.e. without sucking air through the C18 material.

  4. With the plunger still down, draw up 10 µL of solution D and dispense onto a Kimwipe. Keep the plunger down, and repeat 2X. Proceed to step #5 without letting the plunger retract.

  5. Slowly and carefully cycle 8 µl of your diluted sample from #1 above through the equilibrated ZipTip. Do 10 complete cycles while keeping the tip immersed to bind the proteins to the tip. At the end of your last cycle, dispense the liquid into a Kimwipe.

  6. Place the tip in solution D and draw up 8 µl. Dispense onto a Kimwipe and repeat 3X. This step is critical for removing non-peptide components. After the last wash, make sure all the liquid is out of the tip.

  7. Set the pipette for 2.0 µl and elute the peptides by cycling the solution B in the PET tube (from step 2) through the tip for a total of 6 cycles. Cap the tube tightly and store at -15 to -20°C.


Login or Signup to leave a comment
Find your community. Ask questions. Science is better when we troubleshoot together.
Find your community. Ask questions. Science is better when we troubleshoot together.

Have a question?

Contact support@scifind.net or check out our support page.