Expression Cassette Design

Fig. 1. Structure of the expression cassette of a typical bacterial expression plasmid designed to produce an antibody Fab linked to a foreign gene (FG), pelB leader sequences direct penplasmic secretion of the nascent chains. The remainder of the plasmid contains the ampiciilin resistance gene and a plasmid origin of replication.

Papadakis ED, Nicklin SA, Baker AH, White SJ (2004), Promoters and control elements designing expression cassettes for gene therapy, Curr. Gene Ther. 4 89-113. 

In general, expression levels of recombinant proteins in transplastomic plants can be significantly higher than those in nuclear transformants, subject to optimal design of the expression cassette and depending on the nature of the recombinant protein of interest. Clear evidence of an impact of... 

To construct a plasmid for simultaneous expression of A12- and A6-desaturase genes, we designed a pair of primers with homology, respectively, to the 5 end and the 3 end of the seqnence of A12-desaturase expression cassette (hp4d promoter/A12-... 

The I-Scel vector to be injected should be designed such that the expression cassette of interest (e.g., including promoter, transgene, and polyadenylation signal) is flanked by two I-Scel recognition sites (Fig. 1). The expression cassette of the SB vector is flanked by two SB IRs and DRs (Fig. 2). The plasmid DNA should be prepared and purified using a high-purity plasmid preparation kit. DNA concentration and purity can be checked by spectrometry. The ratio of A,7A,. should be between 1.8-2.0. 

The most important considerations for vector design therefore reflect the structure of the expression cassette. Such considerations (as discussed above) include ... 

A synthetic DNA cassette was designed that encoded the repeat sequence Lys-25 (Figure 2). This DNA monomer was synthesized, sequenced, and self-ligated to afford a mixture of DNA concatamers. A 3,000 base pair concatameric gene was iolated from this mixture, which encoded a polymer of Lys-25 with a molecular mass of approximately 90 kD. Bacterial expression of the concatameric gene afforded a protein of the expected molecular mass that accumulates to high levels in E. coli (Figure 3). 

Design to minimize the risk of contact between the operational person and the oral fluid Sample expressed into self-contained vial Sample expressed into separate vial. Verified through field study reports Sample does not overflow test cassette or test strip when transferred by pouring or pipetting ... 

ABC (ATP binding cassette) transporters are ubiquitous proteins that are expressed by prokaryotic and eukaryotic organisms. About 50 human ABC transporters are known, which are divided into seven different subfamilies, designated A-G. 

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