Matrix-assisted laser desorption/ionization-time of flight
(MALDI-TOF) mass spectrometry (MS)
The commercial and the enzymatic keratin hydrolysates
obtained from feather fermentation by B. subtilis were
identified using matrix assisted laser desorption/ionization
time of flight mass spectrometry (MALDI-TOF MS).
Immediately prior to mass spectrometry, acetonitrile/water
(5:95 v:v) and trifluoroacetic acid were added to the
samples. The sample was loaded using a hydrated Zip tip
C18, after which it was washed with water. The sample
was eluted three times with acetonitrile/water (60:40)
containing 0.1% trifluoroacetic acid. An equal volume of
α-cyano-4-hydroxycinnamic acid (CCA) matrix was
added to the sample, and 1 μl of the sample mixture
was spotted directly on a MALDI target for analysis.