Can someone explain me the technique used to measure gene expression in human tissues?
Sal, you can use the reporter gene technique. A reporter gene is used to determine the regulatory potential of an unknown DNA sequence. This involves a promoter sequence that is linked to a detectable reporter genelike luciferase, β-galactosidase/ β-glucuronidase. Another popular method is SAGE ( serial analysis of gene expression). SAGE is used to create a library of short sequence tags which is be used to detect a transcript. The expression level of the transcript is determined by assessing a number of times each tag is detected.
Sal, the Reporter gene is considered as low to mid plex technique, whereas SAGE is considered as a higher plex technique. Another higher plex technique that is quite popular is DNA microarray. This technique is known of as biochip/ DNA chip. The microarray is used to determine expression levels across a huge number of genes or to perform genotyping across a genome.
There are two types of blotting methods which are used for this purpose. Northern and western blotting. The northern technique is used to detect specific RNA molecules which are present within an RNA mixture. The western blotting technique is used for detecting specific protein molecules within a protein mixture.