Ultra-Micro PrepTip™ C18 tips for protein sample preparation.

Now desalt and clean-up a few micro liters of femtomole-level protein in under 30 seconds with Ultra-Micro PrepTip C18 tips for micro;SPE sample preparation. Ultra-Micro PrepTip C18 are available in two sizes: 1-10 µL and 10-100 µL using D10 (P2) or universal pipette tips containing 1 and 10 µL of wide pore C18 resin, fixed at their end such that there is < 0.5 µL dead volume.

Unlike other µSPE products, Ultra-Micro PrepTip brand C18 tips save time by providing a higher capacity, fast, ready-to-use device for off-line sample preparation with excellent precision.
 

In operation, an Ultra-Micro PrepTip brand C18 tip is placed on a standard single or multi-channel pipettor. The sample is aspirated and dispensed through the low back pressure resin to bind the non-polar molecules or small proteins and wash away polar organic impurities. Elution is in 1 - 4 uL of organic solvent. Ultra-Micro PrepTip brand C18 tips are ideal for preparing samples for Mass Spectroscopy or for other analytical techniques.

The 1-10 µL Ultra-Micro PrepTip C18 tips fit a Gilson D10 pipettor.  They have low back pressure and higher capacity than ZipTip® C18 from Millipore®. 

Operating Instructions:

1. Place the Ultra-Micro PrepTip RP onto a micropipette. For best results, DO NOT handle the RP tip with an ungloved hand.

2. Wash the tip with a 10µl aliquot of activating solution (50%acetonitrile in water). Aspirate and dispense the activating solution into and out of the tip 10-15 times in order to extend the hydrophobic chains. Alternative aqueous solvents containing isopropanol or methanol are also suitable for this purpose.

3. Evaporate the residual solvent in the tips by aspirating and expelling air up to 5-10 times. Step #4 should be done immediately after step #3.

4. Using the Ultra-Micro PrepTip RP, aspirate and dispense 10µl of sample just one time and wait 5 seconds to allow the biomolecules to bind. While samples can be applied directly to the Ultra-Micro PrepTip RP, the addition of 0.1-1.0% trifluoroacetic acid or the less hazardous phosphoric acid to a concen-tration of 0.1-0.3% may greatly enhance the binding of biomole-cules to the RP matrix. Increasing the number of aspiration cycles for samples will increase binding for more hydrophobic biomolecules and displace more weakly retained ones, causing your results to be sample dependent. If more capacity is required our MiniSpin products are perfect for this application.

5. Wash the tip twice with 10µl of distilled water to remove any water soluble contaminants.

6. Air dry the resin by aspirating air through the Ultra-Micro PrepTip RP with the micropipette 5-10 times.

7. Elute your sample by aspirating and dispensing a minimum volume of organic solvent mixture (such as 50% acetonitrilein water, 0.1% TFA or formic acid) 10 -15 times. The concentration of organic solvent is very important for both the recovery and purity of the sample. The optimum buffer concentration must be empirically determined for each biomolecule. Tightly bound molecules will require an elution solvent of higher organic content for efficient desorption. Sample recovery can be improved by using an increased volume of elution buffer or by performing a second elution (although the recovered sample will be more dilute).

8. Dispose of PrepTip appropriately after use. Reuse is not recommended cross contamination of samples may occur.