Expression Technologies Inc.
Protein Expression Technologies
Protein expression uses recombinant DNA technology to clone a protein coding DNA
(cDNA) into a plasmid vector and express the protein in a host cell. However, several
problems associated with protein expression in E. coli have been found. The first
obstacle is DNA cloning. Some protein coding cDNAs appear
difficult to be cloned. Many can only be cloned in a vector with the wrong orientation.
contain mutations. Still others cannot be cloned in a particular vector at all. After a cDNA is cloned into a vector, the second problem is that
the protein may not be expressed or the expression is inconsistent. Sometimes it is expressed at
a low level, other times it is simply not expressed. Even after a successful expression, there may
still be protein yield, solubility, stability and activity problems associated with
the expressed protein. Therefore, many scientists claim that protein expression is
an art rather than a science.
Expression Technologies Inc. is dedicated to providing scientific communities with the necessary and sufficient materials and tools for successful recombinant protein expression in E.coli. There are different sections in our web site describing current technologies used in DNA cloning and protein expression. Host cells give protein expression advantages and disadvantages in each host system. Comparison of expression problems in different host systems are described in Problems and hosts. Decisions to express a recombinant protein as full-length, domains, large fusions or small tags are summarized in a table in Domain and fusion. Technologies to overcome difficulties in cDNA cloning and protein expression, that resulted from protein toxicity, are detailed in Toxic protein cloning and expression. Technologies to improve protein yield, solubility, stability, and activity are provided in Protein yield, Protein solubility, Protein stability, and Protein function sections respectively. Growth media are critically important in protein yield, solubility, stability, and activity. Therefore they are listed in a separate section. We also list some examples using our products to overcome DNA cloning and protein expression problems in each section. Our company mission is to provide scientists and the scientific community with the knowledge, products, and protocols necessary for successful DNA cloning and protein expression.