Get Protein Sample Submission Form - Laboratory For Biological Mass ... - Mass-spec Tamu

A mass spectrometer can measure the mass of a molecule only after it converts the molecule to a gas-phase ion. To do so, it imparts an electrical charge to molecules and converts the resultant flux of electrically charged ions into a proportional electrical current that a data system then reads.

The four stages of mass spectrometry are – ionization, acceleration, deflection, and detection. The sample is vaporized before being passed into an ionization chamber where it is bombarded by a stream of electrons emitted by an electrically heated metal coil.

Mass spectrometry is not inherently quantitative because of differences in the ionization efficiency and/or detectability of the many peptides in a given sample, which has sparked the development of methods to determine relative and absolute abundance of proteins in samples.

The first step in the mass spectrometric analysis of compounds is the production of gas phase ions of the compound, basically by electron ionization. This molecular ion undergoes fragmentation. Each primary product ion derived from the molecular ion, in turn, undergoes fragmentation, and so on.

Quantitation is the act of determining a numerical value for the quantity of an analyte in a sample. Quantitative mass spectrometry is an analytical process that answers the important question of 'How much is in my sample? '

In a mass spectrometry experiment, the process sequence of analysis works in five stages, including sample introduction, analyte ionization, mass analysis, ion detection, and data processing.

The amount of sample required to ensure an adequate protein identification attempt is approximately 50-150 fmol (approximately 3-15 ng of a 100 Kd protein).

There are three key stages to a mass spectrometer, and we discuss each in more detail below. Ionization. Molecules in a sample are vaporized (converted to the gas phase by heating). ... Acceleration and Deflection. Next, the ions are sorted ing to mass in two stages – acceleration and deflection. ... Detection.