Tuesday, July 22, 2008

Antisense Technology

At Bio-Synthesis, we offer discovery scale synthesis to mid-scale multi gram quantities for clinical diagnostic applications, in addition to the synthesis of these modified oligos, we routinely assist customers in the design of the oligos that are particularly suited to their applications.

Antisense therapy
Antisense therapy is a form of treatment for genetic disorders or infections. When the genetic sequence of a particular gene is known to be causative of a particular disease, it is possible to synthesize a strand of nucleic acid (DNA, RNA or a chemical analogue) that will bind to the messenger RNA (mRNA) produced by that gene and inactivate it, effectively turning that gene "off". This is because mRNA has to be single stranded for it to be translated. The goal of antisense applications is to shut down activity of a defined gene by blocking transcription or translation within cells. Oligonucleotides for antisense assays must be nuclease resistant against cellular nucleases, must be able to cross cellular membranes and must inherit both high binding affinity and specificity for the target sequence. In many cases, they also must have the ability to induce RNase H cleavage.

Antisense DNA
Antisense molecules interact with complementary strands of nucleic acids, modifying expression of genes. Some regions within a double strand of DNA code for genes, which are usually instructions specifying the order of amino acids in a protein along with regulatory sequences, splicing sites, non coding introns and other complicating details. For a cell to use this information, one strand of the DNA serves as a template for the synthesis of a complementary strand of RNA. The stability of the RNA-DNA duplex in term of hybrization and half-life is crucial to successful gene inhibition. Vigorous research activity in the area of nucleic acid chemistry has been devoted in developing novel base analgos that are resistant to degradation and that possess strong hybridization properties. This includes the classical phosphorothioate linkages, propyne analogs and the latest lock nucleic acid (LNA) base analogs, and peptide nucleic acid (PNA).

Antisense mRNA
Antisense mRNA is an mRNA transcript that is complementary to endogenous mRNA. In other words, it is a non-coding strand complementary to the coding sequence of mRNA; this is similar to negative-sense viral RNA. Introducing a transgenic coding for antisense mRNA is a technique used to block expression of a gene of interest. Radioactively-labeled antisense mRNA can be used to show the level of transcription of genes in various cell types. Some alternative antisense structural types are being experimentally applied as antisense therapy, with at least one antisense therapy approved for use in humans.

1 comment:

Apoptosis Research said...

Hello Dude,

Antisense refers to short DNA or RNA sequences, termed oligonucleotides, which are designed to be complementary to a specific gene sequence. The goal is to alter specific gene expression resulting from the binding of the antisense oligonucleotide to a unique gene sequence. Thanks a lot!