Module 2.1 Sequencing and raw-data QC (outline)

Theme 2: Sequencing and assembly

 

Module 2.1: Sequencing and raw-data QC

Time

Activity description

ILOs                                                                    

9.00-9.30

Lecture: “Introduction to sequencing”


  • Explain when sequencing is an advantage 
  • Overview of relevant sequencing assays and when they should be applied

9.40-10.45

Lecture: “Overview of sequencing technologies”


  • Explain the differences between short-read and long-read sequencing technologies
  • Describe the general idea behind Illumina and Nanopore sequencing, and the differences between them
  • Summarize the difference between single end reads vs paired end reads
  • Outline common reasons for failed sequencing, including sequencing best practices
  • Summarize pros and cons of each sequencing technology

11.00 – 12.00

Interactive Lecture “Sequencing Quality”


  • Understand the fastq format – and why it is gzipped
  • Explain what a phred-score is and how it is used to assess sequencing accuracy
  • Understand when and why read trimming can be necessary

13.00-15.00

Lecture/Practical: “Quality control of sequencing data” 

  • Name and execute software used to facilitate QC on raw data for Nanopore
  • Understand the relation between read sizes and library preparation 
  • Overview of read count in relation to sequencing depth and error assessment
  • Insights into overall read quality on the basis of base quality scoring
  • Introduction to assessment of base contents
  • Generate scripts for performing QC analysis
  • Understand general QC parameters
  • Discuss overall filtration criteria in sequencing
  • Discuss aspects of distinguishing good - from bad -samples

15:00- 16:30

Lecture/Practical:

“Contamination control, sample aggregation, and wrap-up"


  • Introduction to contamination control with Kraken
  • Inspect Kraken report
  • Aggregate QC results into a single report
  • Compare QC results from a whole dataset perspective
  • Discussion of the overall differences in determining QC parameters for Illumina and Nanopore
  • Discuss Advantages and pitfalls of each sequencing platform

 

Details

In this module participants will be introduced to sequencing assays, applicable for species determination and characterization of bacterial isolates. They will get an overview of Illumina and Nanopore sequencing technologies and learn when to apply which technology. Participants will learn how to generate, inspect, and interpret QC reports and how to perform quality control of raw data with Kraken and learn how to inspect the output generated by Kraken.

Finally, participants will be introduced to MutliQC for aggregating QC results, for dataset wide comparison.

By the end of the module, participants will be able to independently execute and assess QC on raw data.



Last modified: Monday, 25 March 2024, 10:48 AM