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]
To generate "5'-end" partial cDNA clones using classic RACE, the first-strand products are generated by reverse transcription (primer extension) from a known gene-specific primer (GSP-RT). Then, a poly(A) tail is appended using terminal deoxynucleotidyltransferase (Tdt) and dATP. Amplification is carried out using three primers. - [Read 5'-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 dealing with carryover contamination in PCR- enzymatic strategy. Repeated use of PCR and manipulation of its products cause aerosols that can contaminate neighboring samples and work areas. Such "carryover contamination" can be prevented by including dUTP in place of dTTP for all amplification reactions. - [Read Dealing with Carryover Contamination in PCR: An Enzymatic Strategy Protocol]
Protocol for desalting of peptides and protein mixtures by RP-HPLC techniques. The RP-HPLC technique can be used to "desalt" peptide or protein samples derived from extraction procedures, from chemical reactions such as reductive alkylation in the presence of urea or guanidine hydrochloride, citraconylation, iodination, or cyanogen bromide cleavage, or recovered from other chromatographic separation. - [Read Desalting of Peptides and Protein Mixtures by RP-HPLC Techniques Protocol]
DNA Electroelution- http://rothlab.ucdavis.edu/protocols/dna-electroelution.html
DNA Electroelution. This protocol describes the purification of DNA by trapping in a high-salt cushion in a "UEA AnalyticalElectroeluter" (IBI). This machine is no longer manufactured, to our knowledge. However, a smiliar device can be easily made from Plexiglas according to the following diagram, taken from Cornel Mulhardt, Molecular Biology and Genomics (2007) Academic Press, p.52: Schimenti Lab - [Read DNA Electroelution]
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]
Protein complexes can be isolated by several different approaches. For example, a protein can be tagged with an epitope such as Flag or TAP and then overexpressed in a target cell, allowing the interacting proteins to be purified. Similarly, epitope tags can be homologously recombined into the endogenous locus ("knocked-in"), allowing protein complexes containing the tagged proteins to be isolated at their natural expression level. - [Read Overview of Affinity Purification in Combination with Mass Spectrometry Protocol]
The multiprotein-DNA complex of interest is formed using the site-specifically derivatized DNA fragment. The complex is then UV-irradiated, initiating covalent cross-linking with proteins in direct physical proximity to the cross-linking agent. Extensive nuclease digestion is performed to eliminate uncross-linked DNA and convert cross-linked DNA to a cross-linked, radiolabeled nucleotide "tag." - [Read Site-Specific Protein-DNA Photo-Cross-Linking: Analysis of Structural Organization of Protein-DNA]
Tubulin is polymerized into microtubules by incubating tubulin at 37°C with GTP. A nucleation seed is added when the purpose is to assay microtubule elongation. Tubulin can also be polymerized for the purposes of recycling the tubulin or labeling the microtubules with fluorescently labeled tubulin. Based on the protocol by Timothy Mitchison of Harvard University.
A single step RNA isolation protocol using Phenol Chloroform Extraction and Acid Guanidinium Thiocyanate. This RNA isolation method uses the fact that guanidinium thiocyanate can simultaneously lyse the cells and inactive cellular RNAses during the initial RNA isolation step allow a single step in the method.
In Vitro Translated Xenopus Mos Kinase Assay Protocol. In response to progesterone, immature Xenopus oocytes mature to eggs that can be fertilized. The Mos protein kinase is essential for oocyte maturation, most likely due to its ability to activate the MAP kinase cascade. This MAP kinase cascade eventually leads to the activation of Cdc2/cyclin B and entry into M phase. In this protocol, tagged Mos kinase is translated in vitro, immunopurified, and used in a kinase assay.
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.
3' Rapid Amplification of cDNA Ends RACE Using PCR Protocol. This protocol contains the steps for 3' end rapid amplification of mRNA by PCR. The first-strand cDNA is synthesized from total or poly(A+) RNA by priming from the poly-A tail of the mRNA using a oligo (dT) adaptor primer. The cDNA is then amplified via PCR using a gene-specific primer and an adaptor primer.
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.