PureSpeed
™
C18
Desalting Tips
Operating Instructions
2
Introduction
Rainin PureSpeed C18 Desalting Tips are an innovative solution for micro-scale reverse phase
desalting. The tips are manufactured in two types to accommodate universal and LTS pipettes.
Each tip contains a small C18 lter at its distal end, with the purpose of desalting peptides
prior to proteomic applications. The tips may be used with the appropriate manual and elec-
tronic single and multichannel pipettes. The protocol contained in this manual describes the
use of the tips when desalting peptides.
Description
There are two different tip types for C18: 10 μL universal tips and 20 μL LTS tips. The 10 μL
traditional tips can be used with universal manual and electronic pipettes, whereas the 10 μL
LTS tips are used with Rainin manual and electronic pipettes with LTS. 20 μL Rainin manual
and electronic pipettes are recommended for the LTS desalting tip version.
Preparation
Prior to carrying out the desalting protocol, prepare the following solutions:
• Tip activation solvent – 100% Acetonitrile
• Tip washing solution – 0.1% (v/v) Trifluoroacetic Acid
• Tip elution solution – 0.1% (v/v)Trifluoroacetic Acid / 90% Acetonitrile
Sample Preparation – Prepare the sample in 0.1% (v/v) TFA. Optimal binding occurs within
this sample buffer.
Pipette Protocol (note the C18 protocol is included in the E4 XLS PureSpeed program)
1. Tip Loading –Mount a C18 tip to the pipette shaft (see table for recommended pipettes) by
pressing the shaft into the wide orifice on the tip. Make sure the tip is securely attached to
the pipette so that there is adequate sealing for up-and-down pipetting.
2. Tip Activation – Set the pipette volume setting to 10 μL or 20 μL depending on the pipette
nominal volume. Pipette 10 μL or 20 μL of tip activation solvent up-and-down five times,
dispensing all solvent from the tip. This action wets the tip and is required to bind the pep-
tide onto the C18 filter.
3. Tip Equilibration – Pipette 10 μL or 20 μL of tip washing solution up-and-down five times.
This step removes the majority of acetonitrile from the filter and prepares the resin for
sample binding. Dispense all solvent from the tip
4. Sample Binding – Pipette 10 μL or 20 μL of peptide sample up-and-down five times. This
step immobilizes the peptides to the C18 silica for washing in the next step.
5. Sample Washing – Pipette 10 μL or 20 μL of tip washing solution up-and-down five
times. Using fresh Tip Washing Solution each time, repeat this step two times. This step
removes the salt from the sample.
6. Sample Elution – Pipette 1 μL to 5 μL of tip elution solution up-and-down five times. This
removes the peptides from the C18 filter and elutes them into the tip elution solution.
7. Dispense sample into an appropriate container ready for the next steps in your workflow.
PureSpeed C18
Desalting Tips
PureSpeed C18
3
Troubleshooting
Problem Possible Cause Suggested Remedy
Tip does not aspirate
liquid
Tip is not mounted correctly, sealing is com-
promised
Make sure that the tip is securely fitted
onto the shaft or nozzle
Pipette seal has malfunctioned Replace seal
Electronic pipette is not charged Charge electronic pipette before use
Tip does not dis-
pense liquid
Tip is not mounted correctly, sealing is com-
promised
Make sure that the tip is securely fitted
onto the shaft or nozzle
Significant back pressure Use pipette blowout to dispense the
residual liquid
Tip does not bind
peptide
Sample contains organic solvents Evaporate solvents using lyophiliza-
tion or centrifugal evacuation
Peptides are not sufficiently hydrophobic to
bind tip
Change pH to modify peptide hydro-
phobicity
Tip has not been pre-wetted with acetonitrile,
or acetonitrile has evaporated from the tip
Make sure that the tip is activated with
100% acetonitrile before use
Tip does not elute
peptide
Peptides are too hydrophobic Use a elution solvent of higher elutro-
pic strength
Final sample is not
sufficiently desalted
Insufficient washing steps in C18 protocol Incorporate additional washing steps
prior to elution
Specifications
Pipette tip: Polypropylene
Media: C18: Irregular, 120 μm, 60 Å pore size
Max Tip Volume: 10 μL universal / 20 μL LTS
Absorptive bed: C18: 0.91 μL
Length: 1.05” universal / 1.65” LTS
Capacity: Up to 10 μg
Operating Temperature: 4°C – 70°C
Working pH Range: 2 to 13
Mass Spectrometry Data
Fig 1: Protein Sequence: Bovine Serum Albumin
220
For more information
Rainin Instrument, LLC.
7500 Edgewater Drive
Oakland, CA 94621
Sales +1 510 564 1600
Service +1 510 564 1600
Subject to technical changes
© 2012 Rainin Instrument LLC
Printed in USA 9920414 Rev A
a METTLER TOLEDO Company
www.mt.com/purespeed
Rainin, Pipetting 360°, LTS, E4, XLS, and PureSpeed are trademarks of Rainin Instrument, LLC and
Mettler-Toledo, Inc.
Ordering Information
Catalog No.
MT Order
No.
Description
PureSpeed Tips and Accessories
PT-LC18-12 17014043 10 µL PureSpeed C18 Desalting Tips, LTS, 12 Tips
PT-C18-12 17014044 10 µL PureSpeed C18 Desalting Tips, Universal, 12 Tips
PT-LC18-96 17014045 10 µL PureSpeed C18 Desalting Tips, LTS, 96 Tips
PT-C18-96 17014046 10 µL PureSpeed C18 Desalting Tips, Universal, 96 Tips
PT-LC18-960 17014047 10 µL PureSpeed C18 Desalting Tips, LTS, 960 Tips
PT-C18-960 17014048 10 µL PureSpeed C18 Desalting Tips, Universal, 960 Tips
Recommended Rainin Pipettes
L-20XLS 17011785 Pipet-Lite XLS – LTS 2.0 to 20 µL
SL-10XLS 17011792 Pipet-Lite XLS – Universal 0.5 to 10 µL
L8-20XLS+ 17013803 Pipet-Lite XLS+ 8-channel – LTS 2.0 to 20 µL
L12-20XLS+ 17013808 Pipet-Lite XLS+ 12-channel – LTS 2.0 to 20 µL
E4-20XLS 17012306 E4 XLS – LTS 2.0 to 20 µL
SE4-10XLS 17012346 E4 XLS – Universal 0.5 to 10 µL
E8-20XLS+ 17013793 E4 XLS+ 8-channel – LTS 2.0 to 20 µL
E12-20XLS+ 17013798 E4 XLS+ 12-channel – LTS 2.0 to 20 µL
PureSpeed Accessories
PT-E4-SD 17012587 E4 XLS Micro SD Card with PureSpeed Protocol
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