LabChip GX/GXII User Manual

Glossary of Terms 263For the purpose of quantitizing the full RNA content in the sample, astraight-line baseline is drawn across the bottom of the sample byfinding the local averages about its endpoint. The area baselineendpoints can be moved on the Graph View after the “Show PeakBaselines” option is selected in the Graph View Properties.Trapezoidal integration from the straight-line baseline to the datasignal is used to calculate the total RNA area. Integration isperformed from the end of the lower marker to the endpoint of thearea baseline. The range from the end of the 5S to the start of the18S peak is termed the Fast Area. This area is calculated in thesame way as the total RNA area.For the purpose of quantitizing the rRNA peaks, a two-pointbaseline is drawn across the bottom of each peak identified asrRNA and the area is computed. These areas and rRNA peakheights and some relevant ratios are made available for display inthe Well Table View. A combination of the quantities is used toassess the quality of the RNA sample.RNA Degrade FactorThis value quantifies the degradation of the ribosomal peaks, whichtypically leads to an increase in the fast area region between the 5Sand the 16S (prokaryote) or 18S (eukaryote) ribosomal peaks. Thequantity is computed as follows:For prokaryote:200 * Fast Area / (Fast Area Time Span) / (Height of 16S +Height of 23S)For eukaryote:200 * Fast Area / (Fast Area Time Span) / (Height of 18S +Height of 28S)As the sample RNA degradation increases, this factor will increase.A value below 10 is obtained with high quality RNA but the usershould determine their own threshold for discriminating betweengood and bad RNA. This quantity can be viewed and reported in theWell Table View.P/N 127170 Rev. 00 LabChip GX User Manual Caliper Life Sciences, Inc.