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- | =Restriction Assay=
| + | {{Imperial/09/TemplateTop}} |
- | === Motivation ===
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- | In order to investigate the effects of the restriction enzymes on the genetic material, we decided to perform a genomic prep, and to perform a restriction digest. Using methylated and unmethylated DNA from different strains,===Solutions to be Prepared Beforehand===
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- | * 5ml Lysis Buffer
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- | ** 25mM Tris
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- | ** 25mM EDTA (pH8.0)
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- | ** 10-15mg Lysosyme
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- | ** 50ug/ml RNaseA
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- | <br>
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- | * 500ul of 5M NaCl Solution
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- | * 1.2ml of 10% SDS
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- | * 2.4ml of 5M Phosphate Acetate
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- | * 700ul of 50mM Tris/ 10mM EDTA
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| | | |
- | === Protocol === | + | |
- | A. Method B – Mehling et. al (1995)
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- | a. 0.5‐1.0 g of cells are resuspended in 5mL lysis buffer (see below)
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- | b. Incubate for 30‐80 min at 37C
| + | === Restriction Protocol === |
- | c. Add 500uL of 5M NaCl solution
| + | <br> |
- | d. Agitate the suspension on a vortex mixer until the cell suspension
| + | Perform for Dam +ve, -ve and TOP10 Strains |
- | becomes translucent
| + | In a PCR tube, mix up the following: <br> |
- | e. Lyse cells by adding 1.2 mL of 10% SDS, mix thoroughly
| + | * 5ul Genome DNA from Prep |
- | f. Incubate lysates for 15‐30 min at 65C
| + | * 2ul of H2O |
- | g. Add 2.4mL of 5M phosphate acetate
| + | * 1ul of 10X BSA |
- | h. Mix by vortexing
| + | * 1ul of 10X B2 |
- | i. Leave on ice for a minimum of 20 min (not much longer than)
| + | * 0.5ul of TaqI |
- | j. Remove precipitate by centrifugation for 30 min at 6000 rpm. Pour
| + | * 0.5ul of DpnII |
- | supernatant into clean tube.
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- | k. Adjust volume of the supernatant to 8mL using isopropanol (about 1
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- | mL each)‐Recover DNA by precipitation
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- | l. Mix and incubate tubes at ‐20C for 30 min
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- | m. Pellet DNA at 20,000 x g for 15 min
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- | n. Pour off supernatant, let pellets dry for 10 min
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- | o. Dissolve precipitate in 700 uL of 50 mM Tris/10mM EDTA (pH 8.0)
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- | p. Transfer the solution to an eppendorf tube (1.5 mL microfuge tube),
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- | Spin off insoluble substances (10 min)
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- | q. Transfer aqueous phase to a 1.5mL microfuge tube
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- | r. Add 75uL 3M sodium acetate and 500uL isopropanol
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- | s. Mix Well and centrifuge solution for 30s to 2 min
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- | t. Wash pellet with cols 70% ethanol, dried and dissolved in 100uL TE
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- | (10mM Tris/1mM EDTA, pH=8.0), or distilled H2O – let pellet dry at
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- | least 40 min before adding the TE buffer.
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- | B. Lysis Buffer
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- | a. 25mM Tris
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- | b. 25mM EDTA, pH 8.0
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- | c. 10‐15 mg Lysosyme
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- | d. 50ug/mL RNaseA
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