Preparing Samples for MALDI

Rule #1. Best results are obtained from clean samples (buffers, salts, detergents.. interfere with MALDI)

Contaminating species are poorly tolerated in MALDI and will require removal if small, uniform matrix/analyte crystals do not form.
Ziptip clean up works well for most protein (C4) and peptide (C18) applications.
If you have a sample that needs to be reconstituted use ultrapure water, acetonitrile is acceptable to use if needed for solubility.
We will add TFA to acidify the sample.

Preparing Samples for LC-ESI

Rule #1. Best results are obtained from clean samples (buffers, salts, detergents.. interfere with ESI, avoid TFA)

Upfront reverse phase liquid chromatography allows for analysis of peptide and protein samples with salts (~< 100 mM) but in most cases not detergents, or polymers.
If you have a sample that needs to be reconstituted use ultrapure water, do not use organic solvents.
We will add FA to acidify the sample.

Definitions (with Respect to Mass Spectrometry)

Resolution = mass/full width at half height

Parts Per Million (ppm)- Refers to mass accuracy = Dm (theoretical to measured) x 10^6/m (measured)

example: measured mass: 999.99 Da theoretical mass: 1000.00 Da error: 10 ppm

Mass Spectrometry Terms Project