External MALDI-TOF-MS instrument DISCONNECTED.

Laser Power 10%









Scan Method

Manual & Steps

Step Instruction Comment
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
Target: Access
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.
13 Save Spectrum After obtaining a satisfactory spectrum, save it to the database.
Run additional scans if necessary.
14 Finish 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
Picolinic acid PA Ethanol 266 oligonucleotides
3-hydroxy picolinic acid HPA Ethanol 337, 355 oligonucleotides
Method Name IS1 IS2 Lens Refl. Refl 2 Delay
RP_(0-1kDa) 19 16.72 8.3 21 9.7 0
RP_(0.5k-4kDa) 19 16.53 8.49 21 9.7 0
RP_(3k-6kDa) 19 16.72 8.55 21 9.7 150
LP_(0.5k-4kDa) 20 18.6 7 N/A N/A 0
LP_(2k-20kDa) 20 18.5 8.5 N/A N/A 150
LP_(10k-150kDa) 20 17.85 9 N/A N/A 300
LP_(30k-300kDa) 20 17.86 9 N/A N/A 500
RN_(0-1kDa) 19 16.75 7.5 21 9.7 0
RN_(0.5k-4kDa) 19 16.76 8.3 21 9.7 0
RN_(2k-10kDa) 19 17.1 8.55 21 8.4 250
LN_(0.5k-20kDa) 20 18.1 8.5 N/A N/A 150