2 质量控制[Quality control]
测序质量 Sequencing Quality
Phred Quality Score（\(Q\)） 可以衡量测序过程中read每个碱基的质量。\(P\)代表该碱基被测序错误的概率，\(Q\) 是与错误概率\(P\)呈对数相关的属性。 公式为 :
Phred quality score is a measure of the quality of the identification of the nucleobases generated by automated DNA sequencing. The Phred quality scores \(Q\) are defined as a property which is logarithmically related to the base-calling error probabilities \(P\). The formular is :
\[Q=-10 log_{10}{P}\]
下表总结了测序质量分数和GC含量。
The following table summarize the sequencing quality scores and GC content.
| Sample | RawReads | Q30 | Q20 | GC |
|---|---|---|---|---|
| C1 | 16170615,16170615 | 93.71%,92.41% | 97.30%,96.37% | 51.16%,51.68% |
| C2 | 19463703,19463703 | 94.37%,92.98% | 97.75%,96.70% | 51.36%,51.87% |
| C3 | 16178102,16178102 | 94.33%,91.96% | 97.73%,96.27% | 51.90%,52.56% |
| T1 | 16125093,16125093 | 93.71%,92.35% | 97.25%,96.32% | 51.41%,51.99% |
| T2 | 16668850,16668850 | 94.40%,92.84% | 97.78%,96.66% | 51.20%,51.67% |
| T3 | 20907830,20907830 | 94.40%,92.52% | 97.75%,96.41% | 51.61%,52.28% |
分列信息 Column Descriptions
Sample : 样本名[The sample Name/ID]
RawReads : 测序原始读数总数[Total number of sequenced raw reads]
Q30 : 符合 Q30 核苷酸百分比[Percentage of nucleotides passed Q30] (Q30: error rate=1/1000)
Q20 : 符合 Q20 核苷酸百分比[Percentage of nucleotides passed Q20] (Q20: error rate=1/100)
GC : GC 含量百分比[Percentage of GC content]
(R1,R2 表示双端测序的末端配对[R1,R2 indicate two mates for paired-end data])
