Molecular Techniques and Methods

Plasmid Purification in Regenerated Silica Resin
(Ex. Qiagen Plasmid Purification Resin)

Copy Right © 2001/ Institute of Molecular Development LLC


INTRODUCTION

Used silica resin can be regenerated more than 50 times without affecting its capacity.


MATERIALS AND SOLUTIONS

Buffer-1 (Resuspension Buffer) (500 ml)
50 mM Tris-HCl (pH8.0) --------------------- 25 ml of 1 M Tris-HCl
10 mM EDTA -------------------------------- 10 ml of 0.5 M EDTA
10 mg RNase A (heat-treated) ---------------- 5 ml of RNase A (10 mg/ml)
Deionized H2O ------------------------------- 460 ml
  • Keep at 4oC.

    Buffer-2 (Lysis Buffer) (500 ml)
    200 mM NaOH ------------------------------- 20 ml of 5 M NaOH
    1% SDS -------------------------------------- 50 ml of 10% SDS
    Deionized H2O -------------------------------- 430 ml

    Buffer-3 (Neutralization Buffer) (500 ml)
    5 M Potassium acetate (pH4.8) ------------------ 245 g
    Glacial acetic acid -------------------------------- 115 ml
    Add deionized H2O to make a final volume of --- 500 ml
  • CRITICAL-Adjust pH to 4.8 with glacial acetic acid.


    Equilibration Buffer (500 ml)
    750 mM NaCl -------------------------- 75 ml of 5 N NaCl
    50 mM MOPS (pH 7.0) ------------------ 50 ml of 0.5 M MOPS
    15% Ethanol --------------------------- 75 ml of 100% Ethanol
    0.15% Triton X-100 --------------------- 750 ul of 100% Triton X-100
    DW ------------------------------------- 300 ml


    Wash Buffer (500 ml)
    1.0 M NaCl --------------------------- 100 ml of 5 M NaCl
    50 mM MOPS (pH 7.0) ------------------- 50 ml of 0.5 M MOPS
    15% Ethanol --------------------------- 75 ml of 100% Ethanol
    DW ------------------------------------ 275 ml


    Elution Buffer (500 ml)
    1.25 M NaCl --------------------------- 125 ml of 5 M NaCl
    50 mM Tris-HCl (pH 8.5) --------------- 25 ml of 1 M Tris-HCl
    15% Ethanol --------------------------- 75 ml of 100% Ethanol
    DW ------------------------------------ 275 ml




    PROCEDURES

    Column Regeneration
    1. Rinse used silica-column with acetone. Fill up the column with acetone.

    2. Rinse column with deionized water. Fill up the column with water.

    3. Repeat acetone and water wash three times.
  • Minimum 3 repeat is essential to remove any cell debris.
  • Any remained cell debris in in the silica column decreases the plasmid yield.

    4. Equilibrate column with 5-10 column volumes of Equilibration buffer.


    Purification
    5. Load the prepared sample from "step 13" [ie., Isolation of Plasmid DNA from E. coli (Alkaline Lysis Method)].

    6. Wash column with 10 column volume (use 20 ml for maxi column) of Wash buffer.

    7. Elute plasmid DNA with 5 column volume (use 10 ml fo maxi column) of Elution buffer.

    8. Add 0.8 vol. of isopropyl alcohol.

    9. Centrifuge for 5 min at 12,000 rpm.

    10. Resuspend plasmid DNA pellet in 200 ul TE.

    11. Add 1/10 volume of 3M Na-acetate and do Phenol:chloroform extraction.
  • Do CHCl3 extraction.

    12. Add 2.5 volume of ethanol and centrifuge for 5 min ar 12,000 rpm.

    13. Remove ethanol and wash DNA pellet with 70% Et-OH.

    14. Dry DNA pellet briefly and resuspend in 50 -200 ul TE.

    15. Measure amounts of DNA in UV-spectrophotometer.
  • 1.0 A260 = 50 ng/ul of DNA

  • 16. DNA solution can be stored at -20oC up to 3 months.
  • For long term storage, keep DNA solution at -70oC.




    NOTES





    KIT INFORMATION




    REFERENCES


  • Please send your comment on this protocol to "editor@MolecularInfo.com".

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