LIT304B 9/3/98 6:51 AM Page A Molecular Biology Grade AG® 50W-X8 Cation Exchange Resin Instruction Manual
LIT304B 9/3/98 6:51 AM Page B Table of Contents Section 1 Introduction ..........................................1 Section 2 Description ............................................2 Section 3 Instructions for Use ..............................3 Section 4 Sample Protocol ....................................4 4.1 4.2 Material Required ...........................................4 Protocol ...........................................................5 Section 5 Reference ...........................
LIT304B 9/3/98 6:51 AM Page 1 Section 1 Introduction Ethidium bromide is used to visualize DNA and RNA preparations because it intercalates between the bases and fluoresces when irradiated with UV light at 300 nm. Propidium iodide, which also intercalates between bases, is used to increase the separation of superhelical and non-supercoiled DNA in cesium chloride gradients. Molecular Biology Grade AG 50WX8 cation exchange resin is useful for removing these dyes, to provide a purified plasmid preparation.
LIT304B 9/3/98 6:51 AM Page 2 Section 2 Description R AG 50W-X8 cation exchange resin is the backbone resin of the Molecular Biology Grade AG 50W-X8 resin. AG 50W-X8 resin is a strong cation exchanger with sulfonic acid functional groups attached to a styrene divinylbenzene copolymer lattice. The Molecular Biology Grade resin is provided in the sodium form. It has been specially equilibrated in Tris buffer at pH 8.0.
LIT304B 9/3/98 6:51 AM Page 4 the resin. Figure 1 shows the removal of (A) ethidium bromide and (B) propidium iodide by Molecular Biology Grade AG 50W-X8 cation exchange resin. R is the resin matrix; SO3- is the functional group covalently attached to the resin. Section 4 Sample Protocol 500 ml beaker Test tube rack for Poly-Prep® chromatography columns Test tubes or other containers to collect DNA 4.
LIT304B 9/3/98 6:51 AM Page 6 4. Dilute DNA with an equal volume of A-50 buffer and apply the DNA sample to the column. Dilution of the sample is necessary to slow the flow rate and allow complete removal of the propidium or ethidium. Use a stopcock to slow the flow rate if necessary. 5. Add 1 bed column (1.5 ml) of A-50 buffer to wash out any remaining DNA. 6. Check DNA sample with UV to insure that the dye has been removed.
LIT304B 9/3/98 6:51 AM Page BC1 Bio-Rad Laboratories, 2000 Alfred Nobel Dr.
