Tissue Biopsy for cancer detection may disappear soon: Genomic method of cancer detection

Tissue Biopsy for cancer detection may disappear soon: Simple blood plasma assay (a liquid biopsy) may be the method of cancer detection in future


Blood plasma,  the straw-colored liquid component of blood that normally holds the blood cells in whole blood in suspension contains dissolved proteins, glucose, clotting factors, mineral  ions,  hormones  and carbon dioxide and DNA. Plasma of cancer patients contains cell-free tumor DNA that carries information on tumor mutations and tumor burden. Though individual mutations have been probed earlier, for the first time a method has been  developed  ( by a team of researchers from UK) for tagged-amplicon deep sequencing (TAm-Seq) which resulted in  screening  5995 genomic bases for low-frequency mutations. Using this method they  identified cancer mutations present in circulating DNA at allele frequencies as low as 2%, with sensitivity and specificity of >97%.They identified mutations throughout the tumor

Transfer PCR: a new method for one step transfer of gene from one plasmid vector to another

A new method called Transfer PCR (TPCR) which  combines PCR amplification of a gene present in a vector / plasmid and subsequent integration of the PCR product into the recipient vector without intermediate product purification and without the need of any commercial kit has been discovered by Researchers from Hebrew University of Jerusalem,and  Weizmann Institute of Science,  Israel.

For DNA cloning, the donor and the recipient plasmids are present in the same reaction tube together with the other reaction components, including primers, reaction buffer and dNTPs. The two primers include sequences, which are complimentary to the target gene at the 3′ end and sequences corresponding to the integration site in the recipient vector at the 5′ end.

{Image courtesy: Journal of Structural Biology)

Example:
The transcription factor IIE α subunit (ΤFIIEα, ∼1300 bp) gene is  in

Light switch for gene expression with potential use in therapeutics

Scientists from  North Carolina State University have identified light-activated molecules to turn gene expression on and off. Triplex-forming oligonucleotides (TFOs) are commonly used molecules that can prevent gene transcription by binding to double-stranded DNA

A light-activated “cage” was attached to a Triplex-forming oligonucleotides. In the absence of light, transcription activity is 100 percent. When exposed to ultraviolet (UV) light, the cage is

Development of a nanofluidic device that combines real-time detection and automated sorting of individual molecules based on their epigenetic state.

Epigenetic modifications, such as DNA and histone methylation, are responsible for regulatory pathways that affect disease. Current epigenetic analyses use bisulfite conversion to identify DNA methylation and chromatin immunoprecipitation to collect molecules bearing a specific histone modification.  A new method  using a nanofluidic device that combines real-time detection and automated sorting of individual molecules based on their epigenetic state has been developed by a group of Scientists from Cornell University.

This device evaluates the fluorescence from labeled epigenetic modifications