A simple and inexpensive chamber for regulating gaseous environment of small culture plates, such as those used for culture of preimplantation embryos, can be constructed using disposable media-filtration devises such as Corning’s 115-ml system. The following is a description of how to make such a device. - [Read Mini-Chamber for Regulating Gaseous Environment During Culture]
In this protocol, a bacterial lysogen is constructed from a recombinant bacteriophage {lambda} encoding a fusion protein of interest. The resulting lysogenic colonies are induced to synthesize the fusion protein, which is then isolated in preparation for functional and biochemical analyses. - [Read Preparation of Lysates Containing Fusion Proteins Encoded by Bacteriophage {lambda} Lysogens]
Recombinant proteins, constructed in pGEX vectors, are fused to glutathione S-transferase (GST) and can be purified to near homogeneity by affinity chromatography on glutathione-agarose. Bound GST-fusion proteins are readily displaced from the column by elution with buffers containing free glutathione. - [Read Purification of Fusion Proteins by Affinity Chromatography on Glutathione Agarose Protocol]
An expression library constructed in a bacteriophage {lambda} vector is plated on an appropriate E. coli strain in the absence of isopropylthio-ß-D-galactoside (IPTG). After 2-4 hours, the plates are moved to 37°C (to stabilize any fusion proteins that are temperature sensitive), and filters impregnated with IPTG are laid on top of the developing plaques. - [Read Screening Expression Libraries Constructed in Bacteriophage Lambda Vectors Protocol]
A cDNA library constructed in a plasmid expression vector of the pUC, pUR, or pEX series is plated on agar medium and then replicated onto filters, which are transferred to plates containing IPTG. After 2-4 hours of induction, the colonies are lysed with chloroform and then screened with appropriate antibodies. - [Read Screening Expression Libraries Constructed in Plasmid Vectors 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]