This calcium phosphate transfection method works best in cell lines that are 1) highly transformed and 2) adherent (Hela, U2OS, SAOS2, AdAH, NPC-KT and obtain from 20% to 100% transfection efficiency depending
on the cell line). Works well for transient experiments but precautions should be used in the design and interpretation of experiments based on the discussion below. Also works
very well for generating stable cell lines. This method is quite sensitive to the amount of input plasmid. - [Read Calcium Phosphate Transfection Method]
Pairs of oligonucleotide primers used in PCR are often designed with restriction sites in their 5' regions. In many cases, the sites are different in the two primers. In this case, amplification generates a target fragment whose termini now carry new restriction sites that can be used for directional cloning into plasmid vectors. The purified fragment and the vector are digested with the appropriate restriction enzymes, ligated together, and transformed into E. coli. - [Read Cloning PCR Products by Addition of Restriction Sites to the Termini of Amplified DNA Protocol]
This assay is performed to detect ubiquitylated proteins in yeast. Yeast that have been transformed with a vector expressing polyhistidine-tagged ubiquitin (Ub) under the control of a copper-inducible promoter are grown, induced with copper, and harvested. Total ubiquitylated proteins are then recovered by nickel-affinity chromatography, and specific proteins are detected by Western blotting. - [Read Detection of Ubiquitylated Proteins in Yeast Protocol]
Protocol describes the use of glufosinate ammonium to select transformed Arabidopsis plants. The major advantage of glufosinate ammonium selection is that it can be performed on plants growing in soil and does not require the use of sterile techniques. - [Read Glufosinate Ammonium Selection of Transformed Arabidopsis Protocol]
BAC DNAs are prepared from 5-ml cultures of BAC-transformed cells by a modification of the standard alkaline lysis method (Preparation of Plasmid DNA by Alkaline Lysis with SDS: Minipreparation). The yield typically varies between 0.1 and 0.4 µg of BAC DNA. - [Read Isolation of BAC DNA from Small-scale Cultures Protocol]
The most commonly used markers for selection of transgenic Arabidopsis are resistance to the antibiotic kanamycin and to the herbicide glufosinate ammonium. Resistance to kanamycin is conferred by a bacterial gene encoding the enzyme neomycin phosphotransferase (NPT). In this protocol, kanamycin-resistant seedlings are selected on solid medium. - [Read Kanamycin Selection of Transformed Arabidopsis Protocol]
RAW 264.7 cells are a macrophage-like, Abelson leukemia virus
transformed cell line derived from BALB/c mice. For routine maintenance in culture (passage), cells are seeded at a confluence of approximately 10% (1 x 106 and 3 x 106 cells in 100-mm and 150-mm plates, respectively) and grown to a confluence of approximately 80%. This procedure requires the cells to be split every two days. - [Read Passage Procedure for RAW 264.7 Cells]
Protocol describes a method to determine the presence of plasmid DNA in an Agrobacterium culture. Compared to selection of transformed Agrobacterium, which can be ambiguous and normally takes several days for resistant colonies to appear, the approach described here is both rapid and accurate. - [Read PCR Analysis of Agrobacterium Protocol]
When more than one bait will be used to screen a single library, significant time and resources can be saved by performing the interactor hunt by interaction mating. In this protocol one strain is transformed with library DNA and the transformants are collected and frozen in aliquots. - [Read Performing a Hunt by Interaction Mating Protocol]
Procedure generates competent cultures of E. coli that can be transformed at high frequencies (5 x 108 transformed colonies/µg of superhelical plasmid DNA). IMPORTANT All steps in this protocol should be carried out aseptically. - [Read Preparation and Transformation of Competent E. coli Protocol]
Protocol reproducibly generates competent cultures of E. coli that yield 1 x 108 to 3 x 108 transformed colonies/µg of plasmid DNA. The protocol works optimally when the bacterial culture is grown at 18°C. If a suitable incubator is not available, a standard bacterial shaker can be set up in a 4°C cold room and regulated to 18°C. - [Read Preparation and Transformation of Competent E. Coli: "Ultra-Competent" Cells Protocol]
Protocol reproducibly generates competent cultures of E. coli that yield 1 x 108 to 3 x 108 transformed colonies/µg of plasmid DNA. The protocol works optimally when the bacterial culture is grown at 18°C. If a suitable incubator is not available, a standard bacterial shaker can be set up in a 4°C cold room and regulated to 18°C. - [Read Preparation and Transformation of Competent E. Coli: "Ultra-Competent" Cells Protocol]
Arabidopsis can be stably transformed using Agrobacterium tumefaciens-mediated transfer of T-DNA. We describe the generation of transgenic plants via root transformation in tissue culture, which can be useful for transforming sterile mutants. - [Read Root Transformation of Arabidopsis Protocol]
Plaques formed by M13 bacteriophages or bacterial colonies transformed by plasmids carrying specific mutations can be detected by hybridization, using a radiolabeled oligonucleotide that forms a perfect duplex with the mutant sequence. Hybridization is carried out under conditions of low stringency that allow the radiolabeled oligonucleotide to anneal to both mutant and wild-type DNAs. - [Read Screening Recombinant Clones for Site-directed Mutagenesis by Hybridization to Radiolabeled Oligos]
Protocol describes a method for transformation of the Tetrahymena using electroporation. The vector is electroporated into cells after mating, where it is incorporated into the DNA of developing macronuclei. Because T. thermophila can be propagated indefinitely without conjugation, transformation of the macronucleus provides a way to obtain stable somatic transformants. DNA vectors transformed using this protocol include those containing drug-resistant versions of Tetrahymena genes. - [Read Transformation of Tetrahymena thermophila by Electroporation Protocol]
The study of transient gene expression provides a useful complement to the study of stably transformed plants. Transient assays offer a quick method of testing the effects of genes, using either phenotypic, molecular, or biochemical readouts. Transient assays based on Agrobacterium-mediated transformation of leaf explants have been described for other plant species, but it is not known how well these assays work in Arabidopsis. - [Read Transient Expression in Protoplasts]
Transient transfection into 293T cells is a convenient way to overexpress and obtain both cellular and extracellular (secreted or membrane) proteins. 293 is a human renal epithelial cell line which is transformed by adenovirus E1A gene product. 293T is a derivative which also express SV40 large T antigen, allowing episomal replication of plasmids containing the SV40 origin and early promoter region. They (both) have the unusual property of being highly transfectable. - [Read Transient Transfection Into 293T Cells Protocol]
In this stage of the protocol, a mammalian cDNA library constructed in a plasmid such as pJG4-5 is transformed into yeast strains containing pBAIT and the lexAop-lacZ reporter plasmid. PJG4-5 expresses the cloned cDNAs from a cassette containing a transcriptional activation domain and other moieties under the control of the yeast GAL1 promoter. - [Read Two-hybrid Systems Stage 2: Selecting an Interactor Protocol]
A Single Stranded Plasmid DNA Isolation Protocol describing the production and isolation of single-stranded DNA (ssDNA) using bacteriophagemid-containing bacteria and helper phage. Infection of the host cells with helper phage allows for packaging of ssDNA into bacteriophage. The ssDNA can then be isolated from phage particles.
The DNA Ligation protocol described here contains the steps required to join together using ligase enzyme both plasmid DNA and insert DNA fragments in order to create a new plasmid. This new ligated plasmid can be transformed after into competent bacteria to produce DNA for mini, midi or maxi-prep isolation.