Title: Efficient manipulation of large biological sequences with the Biostrings package Author: Herve Pages The Biostrings package provides the infrastructure for representing and manipulating large nucleotide and amino acid sequences (up to hundreds of millions of letters) in Bioconductor. As a convenience some Biostrings-based genome data packages are also available: they contain the full genomic sequence for some of the most commonly studied organisms. After an overview of the infrastructure and performance of the Biostrings package, this lab session will examine some typical use cases: basic statistics on large sequences, exact and fuzzy matching problems, sequence alignments, BLAST-like tools, computer-simulated PCR experiments, extraction of the upstream regions for a given list of genes. Also this lab will be an opportunity for the Biostrings developpers to plan further developments based on feedback from the participants.