We now offer to analyze samples in the form of peptide mixtures in-solution, prepared (digested) by customers. The core does not perform the digestion, and in-solution work has significant restrictions on reagents that may be used in your experiment, to avoid contamination and damage to our instruments. In particular no detergents may be used, other than RapiGest SF (Waters) which is mass-spectrometry compatible.
All in-solution samples are subject to mandatory QC checks on our LTQ platform (using 1/5th of the sample) prior to final analysis on a QExactive or Orbitrap instrument. You must carefully review the detailed instructions we provide before embarking on an in-solution digestion experiment.
The in-solution workflow is necessarily restrictive to avoid contamination incidents disrupting the operation of the core. In most cases it will be cheaper, quicker, and easier to follow an in-gel workflow even if it requires working at a large scale or performing further optimization of experimental procedures.
What Does it Cost?
$270 per sample. This cost covers the mandatory QC check, plus main analysis if your sample is clean of MS incompatible contaminants. If your sample is not clean it will be discarded after the QC check and the charge covers the time and expense necessary to clean our QC platform.
What We Do
We accept digested peptide mixtures that must be prepared according to our provided protocol.
We perform a final peptide concentration / desalting of the samples and then inject them on a low-resolution LTQ platform for a QC check. We use 1/5th of the sample for this check, which should not result in significant signal loss in the main analysis. If your sample is clean it is then run on a QExactive or Orbitrap platform.
If you submit a contaminated sample we will meet with you, and require that you follow all guidance given in order to submit further samples. If another sample is submitted that is also contaminated you will no longer be permitted to send in-solution samples.
What You Must Do
Follow the detailed instructions and protocol in our guide (PDF).
Contact us if you are unsure about any aspect of the procedures.
If you have any questions please contact ProteomicsCore@UTSouthwestern.edu before you prepare and submit your samples.