The technique makes use of an Escherichia coli strain expressing the redΑßΓ operon under the control of an inducible promoter. This enables the strain to carry out homologous recombination with only 50-60 bp of homologous sequence. The procedure does not require any DNA ligation and is very rapid. It allows a single gene or region on a cosmid to be replaced by a bi-functional selectable marker (having both an E. coli and an A. fumigatus marker). - [Read A Rapid Method for Generating Gene Deletions in Aspergillus fumigatus Protocol]
Bradford Protein Assay Spectrophotometry. Includes spectrophotometry information and the Bradford protein assay: A spectrophotometer or colorimeter makes use of the transmission of light through a solution to determine the concentration of a solute within the solution. A spectrophtometer differs from a colorimeter in the manner in which light is separated into its component wavelengths. A spectrophotometer uses a prism to separate light and a colorimeter uses filters. - [Read Bradford Protein Assay Spectrophotometry]
EMS is used at concentrations that induce multiple point mutations in each plant, such that mutant alleles of a specific locus are found at a rate of ~1 in 2000-5000 M2 plants. This high rate of mutagenesis makes possible the screening of relatively few plants to find those with the phenotype of interest, a particular advantage if the screen is laborious or if only a small number of genes mutate to the required phenotype. - [Read EMS Mutagenesis of Arabidopsis Seed Protocol]
A. thaliana has a very small haploid genome and this makes obtaining DNA somewhat difficult. The most notable problem is that DNA is usually contaminated with polysaccharide which inhibit restriction enzymes as well as other DNA modifying enzymes. This problem is most easily solved by using young plants which have not accumulated as much polysaccharide as older plants. The best results are obtained with plants that are two to three weeks post germinated. - [Read Plant DNA Extraction Protocol]
Protocol for preparation of KC nuclear extract for in vitro splicing. Protocol makes 3.4 ml of extract for every 4 liter of cells (depending on initial cell concentration). Protocol includes: Procedure, Solutions, BioReagents and Chemicals and protocol hints. - [Read Preparation of KC Nuclear Extract for In Vitro Splicing]
The protocol given makes the method of in situ hybridization easier, faster, more reliable, and available to anyone who can operate a microscope. Includes: Labeling the hybridization probe; Preparation and denaturation of polytene chromosomes
from Drosophila, Chironomus, or other species; Hybridization and detection. - [Read Protocol for Nonradioactive In Situ Hybridization to Polytene Chromosomes with a DIG-labeled DNA]
Recycle tubulin fractions stored at -80¡C after the PC column and store the recycled tubulin in small aliquots for day-to-day use. Generally store recycled tubulin in Injection Buffer (IB) without free GTP. This is done because depolymerization appears to be much better in IB, IB is ideal for microinjections/adding tubulin to extracts, and the absence of free GTP makes polymerization with GMPCPP, a very useful GTP analog that has ~5-10X lower affinity than GTP for tubulin. - [Read Recycling Tubulin Protocol]
Tissue subcellular fractionation and protein extraction for use in mass-spectrometry-based proteomics. Although many methods exist for fractionating proteins, the method described here can capture the majority of subcellular fractions simultaneously at reasonable purity. The scalability of this method makes it amenable to small samples, such as embryonic tissues, in addition to larger tissues. The protocol described is for the general fractionation and extraction of proteins from organs / tissue - [Read Tissue subcellular fractionation and protein extraction for use in mass-spectrometry-based proteomic]
This protocol fixes and prepares embryos for in situ hybridization to visualize transcript expression patterns. It is a modification of the method developed by Tautz and Pfeifle for whole-mount in situ analysis of embryos. Use of the standard hybridization protocol on RNAi-treated embryos results in high background staining, which makes visualization of transcript expression patterns practically impossible. The following modifications eliminate this problem and allow visualization of transcript. - [Read Transcript In Situ Hybridization of Whole-Mount Embryos for Phenotype Analysis of RNAi-Treated]
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 protocol gives general considerations for the design of targeting vectors for transgenic mice. The protocol shares tips in the design of knock-out and knock-in vectors and some of their strategies for producing homologously recombined embryonic stem cells.