Figure 1

Selection of two low-mass ions with differential peak areas in urines from controls and NHL patients after establishing MALDI-MS conditions for low-mass-ion profiling. A. The resolution of mass peaks acquired at variable focus mass. Linear resolution of low-mass peaks was obtained at a focus mass of 500 m/z. B. The effect of laser intensity on overall mass spectrum acquisition. Laser intensity was positively correlated with the area of low-mass peaks (< 1000 m/z). Because low-mass peaks with the highest intensity become saturated at a laser intensity of 5500, the laser intensity for data acquisition was fixed at 5250. C. Typical pattern of mass spectra from urines from controls and NHL patients. D. Box plot of total area of low-mass peaks (< 1000 m/z). The total area of low-mass peaks was obtained from four replicate experiments (cases A to D) using urines from 12 controls (green) and 11 NHL patients (pink).