To ensure efficient proteolytic digestion a control gel plug is digested in parallel with the samples of interest. We are currently using a 1mm O.D. x 2mm tube gel that contains 100 fmole (~7 ng) of bovine albumin as a standard. Three wells in every microwell plate digestion are reserved for this albumin standard. MADLI-TOF performance is validated with this albumin digest and the appropriate calibration mixture for every run. Chromatography and electrospray mass spectrometer performance is validated daily using either the resulting albumin digest or a known protein digest (yeast PGT1 at 100 fmol/uL). Typically 1 to 2 uL are loaded on- column for validation (10 - 20 fmol for the albumin plug or 100 - 200 PGT1). Our criteria for acceptance are based on ion S/N, MS/MS spectra quality, chromatographic separation and reproducability, and ultimately identification score. If you would like to learn more speak with Dr. Hansen.

The stringent quality control of our chromatographic, sample digestion, and ms analysis steps guarantees consistent high quality analysis. In the unlikely event that the control samples do not yeild the defined ms signal we will not charge for the experiments performed.