Molecular Weight Determination

Sample Preparation Guidelines

Samples can be submitted in liquid or solid form.

Liquid or solid samples

1. Purify the protein/peptide

   1. The chromatographic protein/peptide purity should be >90%
   2. Avoid detergents and keep buffer concentration at a minimum. MALDI analysis can be done on samples containing small amounts of salts, urea or detergent, but the best result are obtained with low buffer strength in volatile solvents without detergents 
   3. Minimum amount ~ 10 micrograms

2. Put the protein/peptide into microcentrifuge tube

   1. Use the Eppendorf Safe Lock tube supplied with the kit, or similar tubes from your lab
   2. Lyophilize or speed vac the protein to a solid sample to ensure protein stability during shipment
   3. Alternatively, freeze or refrigerate to +4^oC for cold shipment of the liquid sample

3. Attention

1. Please note that MW determination of intact proteins by mass spectrometry CANNOT be conducted on samples from gels or PVDF membranes!