MALDI Open Access program

Users who run many samples may want to enroll in the MALDI Open Access program in which users run their own samples at a lesser cost than the standard service.

Open Access users need to attend a training session, which can take two hours.

When running samples, users need to bring:

  • their own sample plate
  • pipet tips and other supplies
  • reagents beyond the calibration standards and matrices provided (cyanohydroxycinnamic acid, sinapinic acid, dihydroxybenzoic acid)

Use iLab to reserve the instrument and enter a service request.  A surcharge is applied if users do not follow protocols.

Basic instructions are available in MS Word and pdf formats.

Matrices supplied:

Sinapinic (sinapic, ) 15 mg/ml in 50% acetonitrile, 0.1% trifluoroacetic acid

cyanohydroxycinnamic acid: 8 mg/ml in 80% methanol, 0.1% trifluoroacetic acid

dihydroxybenzoic acid; 10 mg/ml in 33% acetonitrile, 0.1% trifluoracetic acid

Calibrants

protein calibration standard I

ProteinCharge stateAverage mass
myoglobin[M+H]+16952.3
cytochrome c[M+H]+12360.97
ubiquitin I[M+H]+8565.76
myoglobin[M+2H]2+8476.65
cytochome c[M+2H]2+6180.99
insulin[M+H]+5734.51

protein calibration standard II

ProteinCharge stateAverage mass
bovine albumin[M+H]+approx 66.5 KDa
protein A[M+H]+44613
bovine albumin[M+2H]2+approx 33.3 KDa
trypsinogen[M+H]+
23982
protein A[M+2H]2+22307

Bovine albumin is not recommended for calibration because of heterogeneity and adduct formation .

peptide calibration standard

Masses are monoisotopic masses of singly charged peptide

peptide
somatostatin3147.4710
ACTH clip 18-392465.1983
ACTH clip 1-172093.0862
renin substrate1758.9326