Lecture “Algorithms for Sequence Analysis”

Specialized course, M.Sc. Bioinformatics, Saarland University.
Elective course, M.Sc. Computer Science and related, Saarland University.

Prerequisites B.Sc. in Bioinformatics or CS, no special requirements.
Credits 9 ECTS credits
Required time 4V+2Ü (4 hours of lectures, 2 hours of tutorials per week)
Language English
Registration specific to each semester, see below


The following topics will be covered in the course; additional topics may be included, depending on time and current events.

  • exact pattern matching algorithms (simple patterns, no index) and their analysis
  • algorithms based on automata and bit-parallel algorithms
  • full-text index data structures (suffix tree, suffix arrays)
  • several applications of full-text index data structures to bioinformatics, e.g. repeat discovery
  • succinct index data structues (FM index) and algorithms (backward search)
  • approximate pattern matching (simple patterns, with and without index)
  • application: read mapping
  • pairwise sequence alignment: algorithms, variations, speed-ups
  • score matrices and evolutionary Markov processes
  • alignment statistics
  • multiple sequence alignment: models, hardness, heuristics
  • alignment-free methods, k-mers, hashing
  • locality sensitive hashing; min hashing; analysis
  • several applications of alignment-free methods
  • genome assembly
  • motif search and discovery; statistical evaluation of motifs

Scroll down for course schedule and assignments.

Summer 2021

Because of the ongoing CoViD-19 pandemic, this lecture and its associated tutorials will be online only and delivered via Zoom. Lecture recordings and exercise sheets will be linked on this page.

We will discuss the exercises together as a group. For this to work effectively, it is expected that you have watched the lectures or recordings and thought about the problems each week!

Instructor Prof. Dr. Sven Rahmann
Lectures Tue 12:30-14:00 and Thu 08:30-10:00 each week via Zoom. These lectures will be recorded.
Exercises either (A) Tue 14:15-15:45 or (B) Wed 08:30-10:00
Lecture notes TODO
Exams 9 ECTS credits. Dates and details TBD. General information on exams (in German)
Registration Register at the CMS until Friday April 16.
Note Summer 2021 is a virtual online semester. Lectures will be delivered via Zoom. To obtain the Zoom link, please register for the course and then look at the provided link in the CMS.


Note 1: Video recordings of the lectures are only available in the CMS for registered students.

Note 2: Links for assignment submission are sent out by email to registered students. They are also available in the CMS if you lost the email.

Date Topics Slides
Tue 13.04. Exact pattern matching: Naive, Horspool. (Adminstrative issues.) Slides; Admin
Thu 15.04. Automata-based algorithms (NFA: Shift-And; DFA: Knuth-Morris-Pratt) Slides
  Assignment 1, submit via github classroom, invitation sent by email  
Tue 20.04. Bit-parallel algorithms: BNDM; more general patterns Slides
Thu 22.04. A primer on efficient Python programming: Counting motif occurrences in genomes Slides
  Assignment 2, submit via github classroom, invitation sent by email  
Tue 27.04. Full-text index data structures: Suffix trees, Ukkonen’s algorithm. Slides
Thu 29.04. Ukkonen’s algorithm: Skip/count trick analysis. Suffix arrays and enhancements (lcp). Slides
  Assignment 3, submit via github classroom, invitation sent by email  
Tue 04.05. Applications of suffix arrays and linear-time lcp construction (Kasai’s algorithm) Slides above
Thu 06.05. Linear-time suffix array construction: SAIS algorithm Slides
  Assignment 4, submit via github classroom, invitation sent by email  
Tue 11.05.    
Thu 13.05. (Holiday)  
Tue 18.05.    
Thu 20.05.    
Tue 25.05.    
Thu 27.05.    
Tue 01.06.    
Thu 03.06. (Holiday)  
Tue 08.06.    
Thu 10.06.    
Tue 15.06.    
Thu 17.06.    
Tue 22.06.    
Thu 24.06.    
Tue 29.06.    
Thu 01.07.    
Tue 06.07.    
Thu 08.07.    
Tue 13.07.    
Thu 15.07.    
Tue 20.07.    
Thu 23.07. Wrap-up  


Gonzalo Navarro, Mathieu Raffinot
Flexible Pattern Matching in Strings
Cambridge University Press
ISBN: 0-521-03993-2

Dan Gusfield
Algorithms on Strings, Trees and Sequences
Cambridge University Press
ISBN: 0-521-58519-8

David Sankoff und Joseph P. Kruskal
Time Warps, String Edits, and Macromolecules
University of Chicago Press
ISBN: 1-575-86217-4\

Additional research papers may be provided during the lectures.

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