PCR can be used to identify rare DNA sequences in DNA libraries by increasing the abundance of a particular sequence. This is accomplished by subdividing the original library into pools of decreased complexity and screening each pool or group of pools for a given DNA sequence. - [Read PCR-Based Screening of DNA Libraries Protocol]
PCR can be used to identify rare DNA sequences in DNA libraries by increasing the abundance of a particular sequence. This is accomplished by subdividing the original library into pools of decreased complexity and screening each pool or group of pools for a given DNA sequence. A pool that contains the desired clone is subsequently subdivided into smaller pools, each of which is screened using the same PCR protocol that was used for the primary screen. - [Read PCR-Based Screening of DNA Libraries Protocol]
DNA prepared by PCR-mediated gene disruption can be used to transform yeast in gene replacement experiments. This protocol uses two primers, tailed with approximately 50 nucleotides homologous to the gene of interest, that target insertion of the PCR product to that locus. Each primer ends with a universal sequence that is designed to amplify various selectable markers from plasmid templates. - [Read PCR-Mediated Gene Disruption: One-Step Method Protocol]
This protocol describes the preparation of polyethylenimine (PEI)/DNA nanoparticles for targeted gene delivery. This delivery strategy improves the efficiency of gene transfer by enhancing the entry of gene vectors into the desired cells and reducing uptake by nontarget cells. We describe here methods for the conjugation of targeting peptides to PEIs, formation of DNA complexes using the conjugated PEIs or nonconjugated PEIs together with targeting peptides, and cell transfection. - [Read PEI Nanoparticles for Targeted Gene Delivery Protocol]
This protocol describes a method for observing and measuring the movement of RNA molecules in the nucleus of living mammalian cells. Caged fluorescein-labeled DNA oligonucleotides are introduced into living mammalian cells, where they demonstrably hybridize to complementary RNA. After site-specific photoactivation at desired sites within the cell, the RNA movements away from those sites are followed and digitally recorded using a rapid acquisition microscopy system. - [Read Photoactivation-Based Labeling and In Vivo Tracking of RNA Molecules in the Nucleus]
Zygotes can be identified by their unique morphology. They can be easily separated away from nonmated cells using a micromanipulator. This method provides an alternative to the selection of diploid cells on a medium that prevents the growth of haploid parent cells. - [Read Picking Zygotes Protocol]
Protocol describes a method for generating isolated plaques from a stock of bacteriophage lambda. Each plaque derives from infection of a single bacterium by a single bacteriophage particle. Because each plaque contains the progeny of a single virus particle, the bacteriophages derived from a single plaque are essentially genetically identical to one another. - [Read Plating Bacteriophage Lambda Protocol]
Protocol describes a method for plating cells for microinjection onto etched coverslips. The coverslips for microinjection must be marked so that microinjected cells can be identified at time points after injection. - [Read Plating Cells for Microinjection Protocol]
Protocol for precision engineering of plant gene loci by homologous recombination cloning in Escherichia coli. Describe the basis for homologous recombination cloning in E. coli, the available tools and resources, together with a protocol for long range cloning and manipulation of an Arabidopsis thaliana gene locus, to create constructs co-ordinately driven by locus-specific regulatory elements. - [Read Precision Engineering of Plant Gene Loci by Homologous Recombination Cloning in E coli Protocol]
Protocol for precision engineering of plant gene loci by homologous recombination cloning in Escherichia coli. Includes: Key steps in the EL250 RED-HR locus rescue and engineering procedure; Primer design and plasmid constructs; AtSTM gap-repair construct; Targeting construct backbone; Preparation of electrocompetent EL250 cells; Transformation of BAC F24o1 and induction of recombinogenic function in EL250; AtSTM locus rescue from BAC F24o1 by gap-repair HR. - [Read Precision Engineering of Plant Gene Loci by Homologous Recombination Cloning in Escherichia Coli]
This protocol contains methods for pulling microinjection needles using two different models of pipette pullers. The advantage of pulling needles in the laboratory is that a variety of different needle types can be pulled, depending on the samples and cells being injected. An added advantage is cost; once a pipette puller has been purchased, boxes of glass capillaries are inexpensive compared to premade microinjection needles. - [Read Preparation (Pulling) of Needles for Gene Delivery by Microinjection Protocol]
his protocol provides methods for the preparation of protein samples and for loading them into pulled microinjection pipettes. Stock solutions of proteins are thawed, diluted (if desired), centrifuged at high speed to remove aggregates, and kept on ice until loading. Loading into micropipettes can be done using either a "front-loading" or a "backfilling" procedure. - [Read Preparation and Loading of Protein Samples for Microinjection Protocol]
Intermediate filaments (IF) are major cytoskeletal systems of vertebrate and many nonvertebrate cells whose expression is cell-type specific and developmentally regulated. This protocol describes the x-rhodamine labeling of one type of IF, vimentin, and a method for microinjection of the labeled vimentin into cultured cells. IF dynamics can then be examined with fluorescence microscopy. - [Read Preparation and Microinjection of x-Rhodamine-Labeled Vimentin 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]
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.