Understanding Quality Values (Qvs) - Thermo Scientific appliedbiosystems SeqStudio Flex Series User Manual

Chapter 7 View results on the instrument
7
Sequence analysis results
Table 4 Well details (continued)
Result
Spectral calibration status For information, see "Auto-spectral calibration during an injection"
Export status

Understanding Quality Values (QVs)

Quality value ranges
The color of a QV bar indicates the QV of a basecall. The height of the QV bar indicates the relative
value of a QV. A taller bar equates with a higher, better QV.
• Pure basecall with QV ≥20
•
Pure basecall with QV 15–19
•
Pure basecall with QV <15
•
Mixed basecall
Pure basecall versus mixed basecall QVs
• Pure basecalls and mixed basecalls have the same probability of error for the associated basecall
(Quality Value (QV) = –10Log
• High-quality pure basecalls typically have QVs of 20 or higher.
• The distribution of quality values for mixed basecalls differs dramatically from that of pure
basecalls.
• Mixed basecalls have a maximum QV of 20.
• Review all mixed basecalls.
Quality values (QV) and probability of error (Pe)
QV
1
5
10
15
20
25
178
Indicates whether the results were saved to a location in addition to the instrument,
either during data collection or by exporting the Run history.
(Pe), where Pe is Probability of Error.
10
Pe
79.0%
32.0%
10.0%
3.2%
1.0%
0.32%
SeqStudio ™ Flex Series Genetic Analyzer with Instrument Software v1.0 User Guide
Description
QV
30
35
40
45
50
60
on page 150.
Pe
0.10%
0.032%
0.010%
0.0032%
0.0010%
0.00010%