Diagnosis of occult blood in human feces using matrix-assisted laser desorption ionization/time-of-flight mass spectrometry.
BACKGROUND
Guaiac-based chemical tests may be the most cost-effective for routine screening of fecal occult blood (FOB). Unfortunately, such approaches still suffer from the unreliability of the incidence of false-positive and false-negative results in subjects who are on an unrestricted diet. We developed a rapid, automatic, and reliable detection method for FOB using matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS).


METHODS
The water-soluble alpha- and beta-chain hemoglobins (Hb), which are the most predominant proteins found in blood, were used as protein biomarkers for the diagnosis of FOB. The saturated 4-hydroxy-alpha-cyanocinnamic acid (alpha-CHC) solution was found to be the best MALDI matrix for Hb analysis.


RESULTS
The MALDI-TOF MS results were consistent with those provided through conventional chemical analysis, however, the sensitivity for the detection of FOB when using MALDI-TOF MS is approximately 10-100 times higher. In addition, the materials that commonly interfere with the conventional chemical assaying of FOB do not interfere with the detection of the Hb biomarkers during MALDI-TOF MS analysis.


CONCLUSIONS
We demonstrate that MALDI-TOF MS analysis of Hb biomarkers is an alternative approach toward the rapid diagnosis of FOB.
Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan.
Chen-I
CI
Wu
Ching-Chou
CC
Tsai
Chien-Chang
CC
Lu
Pei-Chang
PC
Wu
Deng-Chyang
DC
Wu
Shu-Yao
SY
Lin
Jentaie
J
Shiea
D015415:Biomarkers / Q000032:analysis; D003373:Coumaric Acids / Q000737:chemistry; D006441:Hemoglobin A / Q000032:analysis*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D009780:Occult Blood; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D015415:Biomarkers; D003373:Coumaric Acids; D006454:Hemoglobins; C007175:alpha-cyano-4-hydroxycinnamate; D006441:Hemoglobin A; C020622:hemoglobin B