Statistics and Probability in Evaluation of DNA Evidence

A CIBT Lab Exercise in Molecular Biology



In this lab students will apply statistical analysis to the DNA profiling results of an actual rape case. This lab is an extension of DNA profiling labs which students have previously completed. In part I of this exercise, students will use sets of candy to represent alleles in a particular population at a particular locus. They will sample “alleles” from “populations” at three “loci”, estimate frequencies of alleles in those samples and calculate probabilities of particular combinations of alleles.


Appropriate Levels

Life Sciences, High School, Honors, or Advanced Placement Biology.


Time Required

  • Teacher prep: minimal.
  • In class: Two 40 minute period. This time will also include a discussion of principles with your students.


  • M&Ms
  • autorad facsimilies
  • sample autoradiograph
Copyright for this material is held by Cornell University, the Cornell Institute for Biology Teachers (CIBT), the Center for Nanoscale Systems Institute for Physics Teachers (CIPT), and or West Hill Biological Resources, Inc., 2014. This work may be copied by the original recipient from this web site to provide copies for users working under the direct supervision of the original recipient. All other redistribution of this content without the express written permission of the copyright holder(s) is prohibited.

Price: No Charge


Martha Hamblin, Cornell University, Ithaca, NY

Edited by:
Nancy Wright, Honeoye Central School, Honeoye, NY