Dice and DNA

Abstract

An important part of teaching students how to use the BLAST tool for searching large sequence databases, is to train the students to think critically about the quality of the sequence hits found — both in terms of the statistical significance and how informative the individual hits are. This paper describes how generating truly random sequences by throwing dice can be used to illustrate how unrelated sequences may be found by BLAST, how to judge the statistical significance of the hits, and how the database size influences the statistics.

Keywords:

• BLAST
• teaching exercise
• statistical significance
• bioinformatics

Notes

1 These kinds of dice is available a virtually all shops with role-playing books and equipment. In Denmark I can recommend the “Fantask” shop in central Copenhagen.