Important Sample Preparation Considerations

• Minimize the number of steps in your sample preparation to reduce the opportunities of introducing variation in the subsequent LCMS analysis. Detailed recommendations will be provided during your consultation.


• Lighthouse Proteomics will conduct the sample preparation for you. We have optimized our methods for efficient processing of a wide variety of sample types.

Sample handling guidelines for various sample types

Gel spots or bands: Excised gel bands can easily be contaminated with other proteins from direct contact with your hands when preparing the sample. To minimize contamination, please use nitrile gloves when handling the gel bands and keep ALL EQUIPMENT, which contacts the gel band clean by rinsing with HPLC grade water (including the eppendorf tubes used for the samples). Ship in DRY ICE.

Liquid samples: Wrap sample vial caps (flip top or screw cap) with ParaFilm to avoid inadvertent loss of material from the sample container. Ship in DRY ICE.

Frozen samples: Snap freeze samples using liquid nitrogen for efficient sample preservation. Please do not fill sample vials over 80% to avoid fracturing of the plastic vial by expansion of the sample material. When freezing the samples, please be sure they are in an upright position to keep the sample material away from the lid/cap. Ship in DRY ICE.

Cultured cells (suspension): Rinse cells, sequentially in 2-3 volumes of PBS to remove any media related protein or other soluble materials from the cultured cells. Pellet in an isotonic buffer such as PBS to prevent lysis. Flash freeze the cell pellet after rinsing the cells. Ship in DRY ICE.

Cultured cells (adherent): Rinse cells, sequentially in 2-3 volumes of PBS to remove any media related protein or other soluble materials from the cultured cells. Scrape cells in UREA LYSIS BUFFER (8 M urea, 20 mM HEPES pH 8.0, 1 mM beta-glycerophosphate, 1 mM sodium orthovanadate (activated), 2.5 mM sodium pyrophosphate, 1 mM DTT, 1 mM EDTA) and transfer to 50 mL Falcon tube. Flash freeze the cell slurry in liquid nitrogen. Ship in DRY ICE.