To generate "3'-end" partial cDNA clones, mRNA is reverse-transcribed using a "hybrid" primer (Qtotal, QT) that consists of two mixed bases (GATC/GAC followed by [T]17) and a unique 35-base oligonucleotide sequence (QI-QO). Amplification is then performed using a primer containing part of this sequence (Qouter, Qo) (which now binds to each cDNA at its 3'-end) and a primer derived from the gene of interest, GSP1 (gene-specific primer 1). - [Read 3'-End cDNA Amplification Using Classic RACE Protocol]
New RACE, a variation of RNA ligase-mediated-RACE (RLM-RACE) (Liu and Gorovsky 1993) departs from classic RACE (see 5'-End cDNA Amplification Using Classic RACE) in that an "anchor" primer is attached to the 5'-end of the mRNA before the reverse transcription step; hence the anchor sequence becomes incorporated into the first-strand cDNA if, and only if, the reverse transcription proceeds through the entire length of the mRNA of interest. - [Read 5'-End cDNA Amplification Using New RACE Protocol]
Protocol for 96-well confirmation Yeast PCR. Includes: Clonal purification; Generate a master plate (96-well format); Making a frozen backup stock; Confirmation PCR for one Row; ORF Specific Confirmation PCR --> "A-B" primers (upstream junction); Transfer template DNA to multiwell PCR plate; Prepare and dispense master mix for A-B PCR. - [Read 96-Well Confirmation Yeast PCR Protocol]
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]
Protocol first describes the vector preparation and, then, describes the insert preparation. Vital to have an excellent vector in order to produce a sequencing library. Protocol employs the male-specific coliphage M13 as the sequencing vector. M13 is a filamentous phage with a single-stranded, circular genome. M13 is widely used as a vector because many versions are available commercially and because M13 has certain advantages. - [Read Construction of the Sequencing Library Protocol]
Virus-induced gene silencing (VIGS) uses a virus to deliver a sequence from a gene of interest into a host plant. The virus carrying the fragment of the gene of interest must be capable of replication if dsRNA is to be produced. One or two leaves are inoculated with Agrobacterium strains carrying the VIGS vector possessing the gene fragment. The virus then replicates and spreads throughout the plant, mediating silencing. - [Read Delivery of dsRNA into Plants by VIGS Methodology]
Method uses PCR to amplify and display many cDNAs derived from the mRNAs of a given cell or tissue type. The method relies on two different types of synthetic oligonucleotides: anchored antisense primers and arbitrary sense primers. A typical anchored primer is complementary to approx. 13 nucleotides of the poly(A) tail of mRNA and the adjacent two nucleotides of the transcribed sequence. - [Read Differential Display-PCR Protocol]
Protocol describes a method for electroporating DNA into ES cells, as well as selection methods. Pilot studies should be performed to optimize the conditions for each DNA construct. The selection method described here is one of the most complex. It involves targeting constructs in which the bacterial neomycin-resistance gene disrupts the coding sequence of the mouse gene. - [Read Electroporating DNA into Embryonic Stem (ES) Cells and Selection Methods Protocol]
Method for amplifying DNA enzymatically by the polymerase chain reaction (PCR), including procedures to quickly determine conditions for successful amplification of the sequence and primer sets of interest, and to optimize for specificity, sensitivity, and yield. The first step of PCR simply entails mixing template DNA, two appropriate oligonucleotide primers, Taq or other thermostable DNA polymerases, deoxyribonucleoside triphosphates (dNTPs), and a buffer. - [Read Enzymatic Amplification of DNA by PCR: Standard Procedures and Optimization Protocol]
A set of overlapping synthetic peptides is synthesized, each corresponding to a small segment of the linear sequence of a protein antigen and arrayed on a solid phase. The panel of solid-phase peptides is then probed with a test antibody, and bound antibody is detected using an enzyme-labeled secondary antibody. This method is very rapid and can be extraordinarily successful. - [Read Epitope Mapping Using Synthetic Biotin-Labeled Peptides Protocol]
Protocol for the generation of gene deletions and gene replacements in Escherichia coli O157:H7 using a temperature sensitive allelic exchange system. Technology requires flanking DNA to be cloned into a temperature sensitive vector but the resulting clone allows great flexibility for further modification of the target sequence. It is therefore highly suited to the study of genes in which several rounds of changes are envisaged. - [Read Generation of Gene Deletions and Gene Replacements in Escherichia coli Protocol]
The double-stranded DNA of recombinant plasmid, phagemid, or bacteriophage M13 replicative form DNA is digested with two restriction enzymes whose sites of cleavage both lie between one end of the target DNA and the binding site for universal primer. The enzyme that cleaves nearer the target sequence must generate either a blunt end or a recessed 3' terminus; the other enzyme must generate a four-nucleotide protruding 3' terminus. - [Read Generation of Sets of Nested Deletion Mutants with Exonuclease III Protocol]
This protocol describes the first step in constructing an array: amplification of the predicted ORFs that are to be included in the array. Gene-specific primers containing vector-specific flanking sequences that facilitate recombinational cloning are used to amplify each ORF. A secondary amplification can be used to extend the length of the homologous vector sequence flanking the ORF. - [Read Genome-Wide Analysis of Protein-Protein Interactions Using a Two-Hybrid Array: Amplification of ORFs]
Using hybridization, it is possible to identify a single recombinant that carries the desired target sequence on a filter that carries the imprint of 15,000 or more plaques. - [Read Hybridization of Bacteriophage DNA on Filters Protocol]
Specific molecular components can be efficiently labeled by a combination of three methods: chemical transfection of GFP-fusion constructs, staining of chromosomes with the DNA-specific, fluorescent dye Hoechst 33342, and microinjection of fluorescently conjugated proteins. This procedure provides an example of using all three methods in sequence to label components of living HeLa cells. These methods should be followed in the order presented, but any of them can be omitted when not needed. - [Read Imaging Hoechst-Labeled Chromosomes and Fluorescent Proteins during the Cell Cycle]
Fluorescence microscopy provides a powerful tool for imaging molecular components in living cells. Specific molecular components can be efficiently labeled by a combination of three methods: chemical transfection of GFP-fusion constructs, staining of chromosomes with the DNA-specific, fluorescent dye Hoechst 33342, and microinjection of fluorescently conjugated proteins. This procedure provides an example of using all three methods in sequence to label components of living HeLa cells. - [Read Imaging Hoechst-Labeled Chromosomes and Fluorescent Proteins during the Cell Cycle]
Inverse PCR is used to amplify and clone unknown DNA that flanks one end of a known DNA sequence and for which no primers are available. The technique involves digestion by a restriction enzyme of a preparation of DNA containing the known sequence and its flanking region. The individual restriction fragments (many thousands in the case of total mammalian genomic DNA) are converted into circles by intramolecular ligation, and the circularized DNA is then used as a template in the PCR. - [Read Inverse PCR Protocol II]
Dnase I is used to fragment a radiolabeled target DNA in the presence and absence of a nuclear extract. A "footprint" is generated when a protein binds to the target and protects a specific segment of DNA from the nucleolytic activity of Dnase I. By comparing the electrophoretic mobility of the Dnase I cleavage products to those of a sequence ladder derived from the same DNA fragment, the position(s) of the DNA sequences recognized by DNA-binding proteins can be determined. - [Read Mapping Protein-binding Sites on DNA by Dnase I Footprinting Protocol]
Protocol describes a recently developed method — methylation-specific digital karyotyping (MSDK) — that enables comprehensive and unbiased genome-wide DNA methylation analysis. Using a combination of a methylation-sensitive mapping enzyme (for example, AscI) and a fragmenting enzyme (for example, NlaIII), short sequence tags can be obtained and uniquely mapped to genome location. - [Read Methylation-Specific Digital Karyotyping Protocol]
Information for oligonucleotide details required for PCR. Includes: Primer choice; UPTAG PRIMER; DNTAG PRIMER; UP_45 and DOWN_45 PRIMERS; UP_90 and DOWN_90 PRIMERS. - [Read Oligonucleotide Details for PCR]
This protocol describes the electroporation of the BMH 81-17 mut S strain that is recommended for tranformation of the site directed mutagenesis of dsDNA (See Protocol on Site-Directed Mutagenesis on Double Stranded DNA). BMH 81-17 mut S are a mismatch repair defective (mut S) Escherichia coli strain. The probability that the two mutations will cosegregate during the first round of DNA replication is increased in this strain.
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.