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Expression-of-lac-operon

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Expression-of-lac-operon Powered By Docstoc
					                       Gene Expression of the lac operon using IPTG

Purpose:
To show how genes can be regulated by using the lac operon as an example.

Materials:
    BL21 (DE3) + egfp (un-induced)
    3 agar plates with Kanamycin
    0.5 mM IPTG

Methods:
    Plate 2 kanamycin plates with un-induced BL21(DE3) + egfp.
    Label plates no IPTG and IPTG
    Place in 37°C incubator overnight

   To turn gene on for expression
       Plate 1: Do not add anything
       Plate 2: Using a sterile pipette tip, add 8 µL 0.5 mM IPTG per colony.
       Allow IPTG to soak in
       Incubate at 37°C overnight

      Place the plate under UV light to see bacteria glow.

**Calculation: To make 0.5 mM IPTG, mix 50 µL 1.0 M IPTG + 50 µL LB broth

**I was also going to do a third plate with lactose to see if this would make the bacteria glow
since lactose will express the lac operon. However, we did not have any lactose. This would be
a cool extension of this lab that might be more relatable to the students.


Lab by Ingrid Coulson,
9th grade Honors Biology teacher
Broughton High School, Raleigh, NC
e-mail: icoulson@wcpss.net

				
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posted:12/6/2011
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