Services - DNA Sequencing

Quality Values

Table Explaining the Quality value assigned to each base of a sequencing reaction analyzed by sequencing Analyis ver 5.1. These values are represented by bars placed above the sequencing rection as seen in the print outs or in the electropherogram as viewed with Finch TV.

Quality Value = -10log10 (Pe)
Pe is probability of error
KB basecaller generates QVs from 1 to 99
Typical high quality pure bases will have QV 20-50
Typical high quality mixed bases will have QV 10-50
Size and color of QVs bars are identical for QVs 50-99
0
QV
Pe
1
79%
2
63%
3
50%
4
39%
5
31%
6
25%
7
20%
8
15%
9
12%
10
10%
11
7.9%
12
6.3%
13
5.0%
14
4.0%
15
3.2%
16
2.5%
17
2.0%
18
1.6%
19
1.3%
20
1.0%
QV
Pe
21
0.790%
22
0.630%
23
0.500%
24
0.390%
25
0.310%
26
0.250%
27
0.200%
28
0.150%
29
0.120%
30
0.100%
31
0.079%
32
0.063%
33
0.050%
34
0.040%
35
0.032%
36
0.025%
37
0.020%
38
0.016%
39
0.013%
40
0.010%
QV
Pe
41
0.0079%
42
0.0063%
43
0.0050%
44
0.0039%
45
0.0031%
46
0.0025%
47
0.0020%
48
0.0015%
49
0.0012%
50
0.0010%
60
0.0001%
70
0.00001%
80
0.000001%
90
0.0000001%
99
0.000000012%
0
0
0
0
0
0
0
0
0
0
More information available in Chapter 6 of Sequencing Analysis User Guide
and Chapter 10 of SeqScape User Guide