4 results about "Neutral Charge" patented technology

The present invention relates to a method for purifying one or more target nucleic acid(s), comprising the steps of providing a solution containing the target nucleic acid(s), providing an anion exchange solid phase, characterized in that a switch between an overall positive charge of said anion exchange solid phase to a neutral charge or a negative charge occurs in a pH range of between pH 3 and pH 9, contacting the solution containing the target nucleic acid(s) to said anion exchange solid phase under conditions that allow binding of said target nucleic acid(s) to said solid phase, and eluting the nucleic acid(s) from the anion exchange solid phase using an elution buffer having a pH that is close to or higher than the pH at which the switch between an overall positive charge of said anion exchange solid phase to a neutral charge or a negative charge occurs.

The present invention relates to a method for purifying one or more target nucleic acid(s), comprising the steps of providing a solution containing the target nucleic acid(s), providing an anion exchange solid phase, characterized in that a switch between an overall positive charge of said anion exchange solid phase to a neutral charge or a negative charge occurs in a pH range of between pH 3 and pH 9, contacting the solution containing the target nucleic acid(s) to said anion exchange solid phase under conditions that allow binding of said target nucleic acid(s) to said solid phase, and eluting the nucleic acid(s) from the anion exchange solid phase using an elution buffer having a pH that is close to or higher than the pH at which the switch between an overall positive charge of said anion exchange solid phase to a neutral charge or a negative charge occurs.

Provided is a slurry composition for chemical mechanical polishing (CMP) including two types of colloidal silica abrasive particles, a pH buffer, and a pH adjuster, in which the two types of colloidal silica abrasive particles include first colloidal silica abrasive particles having a neutral charge and second colloidal silica abrasive particles having a negative charge.

The application belongs to the technical field of membrane separation, and particularly relates to a composite membrane and a preparation method and device thereof, which comprises the following steps: S1, a macroporous neutral charge base membrane is selected, a supporting substrate is used to support the base membrane, and the base membrane is assembled into a polytetrafluoroethylene diffusion cell to divide the diffusion cell into two independent chambers; S2, a ligand solution is prepared and injected, and a metal organic framework precursor solution is prepared according to a 1:1 molar ratio; metal organic framework materials with sub-nanometer channels are synthesized in-situ in membrane holes through diffusion effects of two specific ligands in the membrane holes, and the membrane holes of the base membrane are filled with the materials to prepare a high-performance composite membrane, the synthesis process of the membrane material avoids inevitable surface charges and defects of the metal organic framework materials in a traditional membrane preparation method, the mechanical strength of the composite membrane is improved by introducing a polymer base, and the sub-nanometer channels of the neutral charge metal organic framework materials are used for lithium-magnesium separation.