The Protein Man's Blog | A Discussion of Protein Research

Sputum Liquefaction: from viscous, heterogeneous mucus to equivalent, homogenous samples

Sputum processing has one main purpose; to render the viscous, heterogeneous specimen to a homogenous state (evenly distributed suspension). This homogenous suspension will be dispensed into multiple aliquots for cryopreservation, smear microscopy, gram stain, and culture. Each aliquot should be representative of the original specimen. This can be accomplished through the process of sputum liquefaction.

Reporter Gene Assays and their applications

Reporter gene assays are paramount for study of regulation of gene expression by gene regulatory elements (cis-acting factors), transcription factors or exogenous regulators (trans-acting factors). In reporter gene assays, the activity of a reporter gene is measured. A reporter gene is joined to a target regulatory DNA sequence in an expression vector, which is then transfected into the cell type of choice. The reporter gene is transcribed and translated in the cells and its activity is measured to access the strength or function of the target regulatory DNA sequence or study effects of transcription factors or potential drugs etc.

EDC is the most popular zero-length crosslinker for biochemical conjugations because it can efficiently form conjugates between two protein molecules, between a protein and a peptide, and between proteins and oligonucleotides, and with small molecules.

There are several contemporary methods for protein purification. Some techniques are very powerful, such as reverse phase chromatography, immunoadsorption, or affinity chromatography. However, these methods may ultimately denature protein and negatively impact the desired product. Likewise, recombinant proteins recovered from inclusion bodies are often aggregated and nonfunctional. In all of these situations, the purified protein product must be renatured for further use.