miniPCR bio
TM
Chopped! Using CRISPR/Cas9 to cut DNA - Instructor's and Student's Guide
Version: 1.0 - Release: May 2022 - © 2022 by miniPCR bio™
P./49
Instructor's Guide
Differentiation
This lab serves as an introduction to the mechanisms of CRISPR/Cas9 and how the system can be
used to specifically target a given DNA sequence. With simple modifications, this activity can be
used effectively in classes ranging from introductory high school through advanced college-level
classes.
Introductory classes: Focus on the fact that the same Cas9 nuclease can be used to cut any target
DNA sequence just by changing the gRNA used. Spending more time on the paper model in the
pre-lab activity will aid in student understanding of this key concept. The standard introduction and
review questions for this lab take this approach.
Advanced classes: Have students complete the optional advanced questions (page 30 & 37) to use
probability to show how specific the CRISPR/Cas system is in targeting the genome for editing.
You may also wish to introduce discussion of the PAM sequence which this lab omits in the interest
of simplicity. You can find discussion of the PAM sequence in Notes on lab design on the previous
page. Introduction of the PAM sequence will affect how probabilities are calculated in the Using
mathematical thinking section of the Advanced questions.
Pre-lab activity alternative: the pre-lab activity in the guide has students cutting out paper models
of the gRNA and DNA to determine the expected band sizes. If you do not wish to use the paper
model cutouts, you can have your students analyze the sequences electronically with the provided
full sequences (https://links.minipcr.com/chopped_prelab) or skip the pre-lab altogether and just
provide the expected band sizes to your students (found on page 44).
