What Are the Advantages and Disadvantages to Using Gene Chip

Question

Examlex · Accepted Answer

The Answer is New technologies now allow scientists to produce microarrays that contain thousands of hybridization probes on a single membrane or other solid support.
Microarrays of oligonucleotide or cDNA probes are produced in several ways: (1)microsynthesis of oligonucleotides in situ (on the chip),(2)spotting prefabricated oligonucleotide probes on solid supports,and (3)spotting DNA fragments or cDNAs on the supports.The probes on the microarrays are then hybridized to labeled (usually with a fluorescent tag)RNA or cDNA samples.The amount of RNA or cDNA hybridized to each probe in a microarray is quantified by using sophisticated scanners with micrometer resolution and appropriate computer software.As knowledge in the field has advanced,geneticists have been able to study the expression of more and more genes.Now,for the first time,they can study the expression of all the genes of an organism simultaneously.The ability to analyze the expression of entire genomes will enhance the current explosion of new information in biology and will eventually lead to an understanding of the normal process of human development and the causes of at least some human diseases.Array hybridizations and gene chips can be used to determine whether genes are transcribed,but they provide no information about the translation of the gene transcripts.Thus,biologists often use antibodies to detect the protein products of genes of interest.Western blots are used to detect proteins separated by electrophoresis,and antibodies coupled to fluorescent compounds are used to detect the location of proteins in vivo.However,both of these approaches provide only a single time-point assay of a protein in a cell,tissue,or organism.The discovery of a naturally occurring fluorescent protein,the green fluorescent protein (GFP)of the jellyfish Aequorea victoria,has provided a powerful tool that can be used to study gene expression at the protein level.GFP is now being used to monitor the synthesis and localization of specific proteins in a wide variety of living cells.These studies entail constructing fusion genes that contain the nucleotide sequence encoding GFP,coupled in frame to the nucleotide sequence encoding the protein of interest; introducing the chimeric gene into cells by transformation; and studying the fluorescence of the fusion protein in transgenic cells exposed to blue or UV light.Because GFP is a small protein,it can often be coupled to proteins without interfering with their activity or interaction with other cellular components.

What Are the Advantages and Disadvantages to Using Gene Chip

Definitions: