G25脱盐柱使用指南.pptx

Desalting column protocol;Matrix Sephadex? G-25 Fine, cross-linked dextran Bed volume 53 ml Bed height 100 mm i.d. 26 mm separation of high (Mr 5 000) from low molecular weight substances (Mr 1 000). Storage +4 to +30 °20% ethanol ;;;;;Sephadex G-10 is well suited for the separation of biomolecules such as peptides (Mr 700) from smaller molecules (Mr 100). Sephadex G-50 is suitable for the separation of molecules Mr 30 000 from molecules Mr 1 500 such as labeled protein or DNA from unconjugated dyes. The medium is often used to remove small nucleotides from longer chain nucleic acids. Sephadex G-25 is recommended for the majority of group separations involving globular proteins. These media are excellent for removing salt and other small contaminants away from molecules that are greater than Mr 5000.;sample volumes of up to 30% of the total volume of the desalting column can be processed. not exceed approximately 70 mg/ml。 ;Column: HiTrap Desalting, 1 × 5 ml, 3 × 5 ml, 5 × 5 ml Sample: 2 mg/ml BSA in 50 mM sodium phosphate, 0.5 M sodium chloride, pH 7.0 Sample volume: 28% × Vt (1.4, 4.3 and 7.1 ml respectively) Buffer: 50 mM sodium phosphate, 0.15 M sodium chloride, pH 7.0 Flow rate: 5 ml/min;Storage Store unused media 4°C to 30°C in 20% ethanol. Do not freeze. Wash used media with 2 column volumes of distilled water followed by 2 column volumes of 20% ethanol. Store at 4°C to 30°C. Alternatively, wash with 2 column volumes of distilled water followed by 2 column volumes 0.01 M NaOH. Sodium hydroxide solution is bacteriostatic, easily disposed of and does not shrink the medium. Degas the ethanol/water mixture thoroughly and use a low flow rate, checking the back pressure as the column equilibrates. Avoid changes in temperature which may cause air bubbles in the packing.