Assessment of insert sizes and adapter content in fastq data from NexteraXT libraries

Area of Science:

• Genomics
• Bioinformatics
• Next-Generation Sequencing

Background:

• The Illumina NexteraXT transposon protocol generates paired-end libraries cost-effectively.
• High sensitivity to DNA concentration leads to variable insert sizes in NexteraXT libraries.
• Small insert sizes can result in adapter contamination and reduced read length.

Purpose of the Study:

• To develop a protocol for identifying and removing adapter sequences from Illumina sequencing reads.
• To address challenges posed by small insert sizes in Next-Generation Sequencing data.
• To provide a method applicable to NexteraXT libraries and other Illumina datasets.

Main Methods:

• Utilized publicly available bioinformatics tools for data analysis.
• Developed a protocol to identify read pairs with small insert sizes.
• Implemented steps to check adapter sequences and trim them from reads.
• The protocol does not require a reference genome or prior knowledge of adapter sequences.

Main Results:

• Successfully identified read pairs likely containing adapter sequences due to small insert sizes.
• Provided a method for accurate adapter sequence identification and removal.
• Demonstrated the protocol's effectiveness without needing a reference genome.

Conclusions:

• The developed protocol offers a robust solution for managing adapter contamination in Illumina sequencing data.
• This method is particularly beneficial for NexteraXT libraries but broadly applicable to other Illumina datasets.
• Efficient adapter trimming improves the quality and usability of sequencing data for downstream analysis.