MALDI Sample Requirements
Requirements
- Optimal concentration is 10 mM. One micromolar will work if the sample is “clean”.
- Samples should be in water (at best) or in low salt buffer. Samples should not contain DMSO, detergents, or glycerol. However, if it is not possible make sure that the concentration is <1%. An additional fee ($19/sample) will be charged for sample cleanup (desalting). Please refer to the salt/buffer/detergent tolerance table below.
- Protein digestion fee* is $24/sample. If samples are in gel, the stain should be mass spec compatible (eg. coomassie or spyro ruby). Please do not overstain and place the cut up gels in MeOH.
Salt Tolerance Table
| Buffer/Salt/ Detergent | Concentration, mM | Concentration, wt% |
|---|---|---|
| Ammonium Bicarbonate | 50 | 0.4 |
| CHAPS | 0.16 | 0.01 |
| Glycerol | 130 | 1.2 |
| Guanidine HCl | 250 | 2.4 |
| Hepes | 100 | 2.4 |
| Phosphate Buffer | 10 | 0.12 |
| SDS | 0.35 | 0.01 |
| Sodium Azide | 15 | 0.1 |
| Sodium Chloride | 50 | 0.29 |
| Sodium Acetate | 50 | 0.41 |
| Tris Buffer | 100 | 1.0 |
| Triton X, NP-40 | 1.7 | 0.1 |
| Urea | 500 | 3.0 |