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* Sample quality assessment: DNA/RNA integrity is assessed using a fluorometer or electrophoresis assay (e.g., RIN value).
* Standardization: Using standardized processes for fragmentation, end-repair, adapter ligation, and PCR amplification reduces operator variability.
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* Internal Quality Control: The sequencer's built-in quality control module (such as Illumina's Sequence Control Software) monitors signal intensity, error rate, and cluster density in real time.
* Standard Insertion: Base call errors are corrected using standards with known sequences (such as the PhiX control).
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* Raw Data QC: Read quality, GC content, and adapter contamination are assessed using tools such as FastQC.
* Post-alignment Analysis: Calculation of coverage uniformity (such as BedTools), duplication rate (such as Picard MarkDuplicates), and target region capture efficiency (for targeted sequencing).
* Statistical Consistency Test: Analyze the correlation and variability of replicate samples using tools such as R packages (DESeq2 for transcriptomes) or custom scripts.
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* Generate quality control reports and address weaknesses (such as PCR bias) by optimizing the protocol or introducing technologies such as UMIs (Unique Molecular Identifiers).