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.
| SampleID | RawReads | Q30 | Q20 | GC |
|---|---|---|---|---|
| P-1 | 147937217,147937217 | 47.99%,91.47% | 63.95%,96.26% | 36.48%,46.95% |
| P-2 | 102099738,102099738 | 48.15%,91.59% | 64.10%,96.29% | 36.24%,46.75% |
| P-3 | 105994125,105994125 | 48.15%,91.79% | 64.10%,96.40% | 36.30%,46.74% |
| P-4 | 70449698,70449698 | 48.24%,91.78% | 64.18%,96.35% | 36.33%,46.71% |
| T-1 | 114441598,114441598 | 48.79%,92.13% | 64.86%,96.56% | 35.79%,47.03% |
| T-2 | 145418174,145418174 | 48.89%,92.20% | 64.96%,96.59% | 35.72%,46.95% |
| T-3 | 88079461,88079461 | 48.95%,92.29% | 65.01%,96.62% | 35.46%,46.69% |
| T-4 | 89771241,89771241 | 48.72%,92.26% | 64.79%,96.62% | 35.87%,47.08% |
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])
