LabChip GX/GXII User Manual

Glossary of Terms 262This fit to the ladder peak data can be viewed by selecting StandardCurve from the Analysis menu. After sample peaks have beensized, the system peaks are identified and excluded based on theirsize. Any peak of size greater than the lower marker but less thanthe Min. Sample Size specified in the Assay Analysis Window islabeled a system peak and excluded from concentration and purityanalysis.To determine sample peak concentration, the peak areas are firstcorrected to compensate for the fact that the fluorescenceintensities are sampled at a constant time interval so slower movingproteins spend more time under the detector than fast movingproteins. The peak concentration is then calculated using the ladderpeak areas and concentration for the ladder supplied in the AssayAnalysis Window. The concentration is adjusted for the differingdilution ratios of sample and ladder.To quantitize the sample peak concentration based on a differentstandard, the new standard must be added into each sample well ata known concentration. The analysis settings provide a SamplePeak Quantitation option using the peak area and concentration ofthe User Standard instead of the ladder concentrations.RNA Assay AnalysisRNA analysis initially progresses similarly to DNA analysis exceptthat the baseline for RNA peaks is calculated using a spline-fit,much like the baseline used for the Baseline Subtraction option.However, this computed fit is not subtracted from the data; instead itis used to determine the peak height and to limit the peak extends.The RNA ladder is similar to the DNA ladder but does not containan upper marker. RNA sample data is aligned with the lower makerand then the sample peaks are sized using point-to-pointinterpolation between ladder peaks. The most prominent peaksfound within predefined size windows are identified as ribosomalrRNA genes 5S, 18S and 28S (for eukaryote RNA), 16S and 23S(for prokaryote RNA).P/N 127170 Rev. 00 LabChip GX User Manual Caliper Life Sciences, Inc.