The sensitivity, or limit of detection, of each system is also an important performance specification and is one factor that distinguishes the two automated electrophoresis systems.
Sensitivity becomes particularly important when protein concentrations are low or when purity is being evaluated. The separation of the E. coli lysate on both systems (Figure 2) illustrates that the Experion system is more sensitive than the bioanalyzer; when an identical sample was loaded onto both systems, the peaks in the Experion electropherogram were of a much higher intensity than those in the bioanalyzer electropherogram.
The sensitivity of both systems was also evaluated by comparing the signal-to-noise
ratio produced by a dilute sample of CA (2.5 ng/l). The peak generated
by this sample was not identified by the protein 200 plus assay (Figure
5); however, based on the peak height generated on the Experion system,
a mean signal-to-noise ratio of 20.5 was calculated. The electropherogram
shown in Figure 5A illustrates the extent to which the fluorescence signal
associated with this CA sample rises above the background with the Experion
system. The low detection limit of the Experion Pro260