protocol describes a method for the synchronization of cell populations using centrifugal elutriation. The method relies on the fact that cell size increases linearly as cells proceed through the cell cycle. Cells of similar size (and cell cycle phase) are eluted stepwise from the cell chamber, with the smallest size (those in early G1) being eluted first. Using this procedure, it is possible to obtain relatively pure populations of cells at various points in G1, S, and G2/M. - [Read Cell Synchronization Using Centrifugal Elutriation Protocol]
This protocol describes a method for the synchronization of cell populations using centrifugal elutriation. The method relies on the fact that cell size increases linearly as cells proceed through the cell cycle. Cells of similar size (and cell cycle phase) are eluted stepwise from the cell chamber, with the smallest size (those in early G1) being eluted first. Using this procedure, it is possible to obtain relatively pure populations of cells at various points in G1, S, and G2/M. - [Read Cell Synchronization Using Centrifugal Elutriation Protocol]
In this protocol, the DNA-binding capacity of Wizard MagneSil particles is used to capture and release a consistent amount of DNA (100 ng) across a wide range of samples. At the end of the procedure, the DNA is eluted into 100 µl Elution Buffer to give a final concentration of 1 ng/µl, relieving the need for postpurification DNA quantitation. - [Read DNA IQ Isolation of Genomic DNA from Stains and Buccal Swabs Protocol]
Transfer of proteins from a Tris/glycine SDS-polyacrylamide gel to a membrane using the submerged method is achieved by placing the gel next to a piece of nitrocellulose filter, submerging this sandwich in a large volume of transfer buffer in a transfer tank, and running current from one side of the transfer tank to another. The proteins are then eluted by transferring them from the gel onto the filter. - [Read Immunoblotting: Submerged Electrophoretic Transfer of Proteins from Gels to Membranes Protocol]
Protocol for the purification of DNA recovered from agarose and polyacrylamide gels by anion-exchange chromatography. Fragments of DNA recovered from agarose gels are sometimes poor templates or substrates in subsequent enzymatic reactions. This problem can be solved by binding the DNA to a positively charged matrix, such as DEAE-Sephadex or DEAE-Sephacel, in buffers of low ionic strength. After washing the matrix, the DNA is eluted by raising the strength of the buffer. - [Read Purification of DNA Recovered Anion-exchange Chromatography Protocol]
Recombinant proteins engineered to have a polyhistidine tail at either the carboxyl or amino terminus can easily be purified in one step by affinity chromatography on a resin carrying chelated nickel ions. Chromatography can be carried out in column or batch formats. After unbound proteins are washed away, the target protein is eluted using imidazole, which typically preserves the antigenic and functional features of the protein. - [Read Purification of Histidine-tagged Proteins by Immobilized Ni2+ Absorption Chromatography Protocol]
Immobilized metal-ion affinity chromatography (IMAC) is suitable for the purification of proteins under denaturing conditions. Either guanidine-HCl or urea can be used, although guanidine-HCl is a stronger denaturant than urea. Proteins that have been adsorbed to the column in the presence of guanidine-binding buffer may be washed with urea-binding buffer and eluted with urea elution buffer. - [Read Purification of Histidine-Tagged Proteins under Denaturing Conditions Using IMAC Protocol]
Protocol for purification of synthetic oligonucleotides by polyacrylamide gel electrophoresis. As a rule of thumb, oligonucleotides >25 nucleotides should be purified by polyacrylamide gel electrophoresis, as should oligonucleotides of any length that yield anomalous results. After electrophoresis, the oligonucleotide is eluted from the gel and concentrated by reversed-phase chromatography on Sep-Pak C18 columns. - [Read Purification of Synthetic Oligonucleotides by Polyacrylamide Gel Electrophoresis Protocol]
Technique yields a heterogeneous population of short radiolabeled molecules 200-300 nucleotides in length. These probes are synthesized, as in Synthesis of Single-stranded DNA Probes of Defined Length from Bacteriophage M13 Templates, by extension of an oligonucleotide primer on a single-stranded DNA template. The radiolabeled products of the reaction are then separated from the template by electrophoresis through a denaturing gel from which they are eluted directly into hybridization buffer. - [Read Synthesis of Single-stranded DNA Probes of Heterogeneous Length from Bacteriophage M13 Templates]
A protocol for the selection of Phage Antibodies using Immobilized Antigen. This method describes the selection of antibodies from bacteriophage antibody libraries that recognize a specific antigen. The phage display library of antibody-displaying phage particles is exposed to antigen attached to a solid substrate (Nunc Immuno™ tubes). The phage particles with affinity for antigen bind to the immobilized antigen and are selected from the library of phage expressing antibodies.