Guidelines for sample preparation for Intact Protein Analysis on BioAccord 1 are found below, or can be downloaded as a pdf.
Please aim for a protein concentration in the range 10 - 50 micromoles. Depending on the ionisation of your protein, you may need to adjust the final concentration. Do not submit samples which have a concentration greater than 100 μM as you will likely damage the instrument.
Over concentrated samples will be flagged to MS Staff and will lead to increased chemical noise, poor mass resolution, blockage in the sample delivery lines and contamination of the mass spectrometer. Please make sure that there are no hard particles in the solution or precipitation at the bottom of your sample vial, and that the solution is not jelly-like or cloudy.
Only standard 2 ml mass spec sample vials with a pre-slit septum on the top of the lid should be used. The vials are available from CRL stores. No taller vials or vials with hard lids can be used.
BioAccord 1 uses electrospray ionisation which is only compatible with volatile organic solvents and water. Samples have to be cleaned of salts: high salt concentrations are not compatible with ESI. Please follow the protocol below for sample preparation:
- Purify your protein using a suitable filter (eg. Amicon MWCO or Bio-Spin column) to remove salts and impurities. LC purification would also be appropriate.
- Resuspend your protein in acidified aqueous acetonitrile (ideally 5% MeCN(aq) + 0.1% FA) to a final protein concentration between 10-50 micromoles.
- Place the solution in a standard 2 mL mass spec sample vial with a screw cap lid and pre-slit septum on the top (available from stores). Other 9mm insert vials such as Thermo Scientific SureSTART microvials may also be used so long as they have pre-slit screw cap lids and are the same height as the standard 2 mL vials.
- Do not use Tetrabutyl ammonium (TBA) or Trifluoroacetic acid (TFA) in your samples (or any other ion-pairing agents) these will contaminate all subsequent samples run on the system.
