|1||Choose the matrix for your sample|
|2||verify sample is completely dry||Poor vacuum (poor signal and resolution) as well as long transfer times will result from wet samples.|
|3||Check status lights on the instrument panel||Mains: Green
System: Ready or Warm-up
|4||Remove sample plate||Always store sample carrier in instrument to ensure that the next person can find it|
|5||Place plate on carrier||Sample “coin chip” is keyed to only fit one way. Ensure plate sits flush with the top of the carrier and sample plate is flat. Otherwise, sample may scratch sealing surface and cause a leak.|
|6||Load Plate into Loading Dock|
|7||Eject||Press the Eject Button in the starting screen (or the large green button on the side of the MS-MALDI to insert your sample|
|8||Select Method||The naming convention is for basic operation “RP_(0.5k-4kDa).par”
First character = TOF mode: L = linear / R = Reflectron
Second Character = polarity: P = positive / N = Negative
Third phrase = optimized and calibrated molecular weight range
|9||Set Scan Parameters|
|10||Select correct positions of the sample in the plate view|
|11||Set Laser Parameters||Select an appropriate number of shots and frequency of shots for your sample. Also, set the laser offset to approximately 10-15%.|
|12||Press start||Move the crosshairs around the sample (left click with mouse) to find a good spot. You may also need to change the aforementioned settings. Note: if you are getting a “hump” near the left of the spectrum, you are likely using too much laser power.|
After obtaining a satisfactory spectrum, save it to the database.
Run additional scans if necessary.
Press the Eject Button in the starting screen (or the large green button on the side of the MALDI.
Remove the sample and insert the plate back into MALDI.
Press the Eject Button again and the plate should be inside MALDI.
Properly dispose of the sample.
|Compound||Other Names||Solvent||Wavelength (nm)||Applications|
|2,5-dihydroxy benzoic acid||DHB Gentisic acid||acetonitrile, water, methanol, acetone, chloroform||337, 355, 266||peptides, nucleotides, oligonucleotides, oligosaccharides|
|3,5-dimethoxy-4-hydroxycinnamic acid||sinapic acid; sinapinic acid; SA||acetonitrile, water, acetone, chloroform||337, 355, 266||peptides, proteins, lipids|
|4-hydroxy-3-methoxycinnamic acid||ferulic acid||acetonitrile, water,propanol||337, 355, 266||proteins|
|α-Cyano-4-hydroxycinnamic acid||CHCA||acetonitrile, water,ethanol, acetone||337, 355||peptides, lipids, nucleotides|
|3-hydroxy picolinic acid||HPA||Ethanol||337, 355||oligonucleotides|
|Method Name||IS1||IS2||Lens||Refl.||Refl 2||Delay|