Biochips is a broad term generally refers to miniaturization of bioanalytical devices, so its patterns will be all-inclusive, on the development of its technology and the industry is concerned, it can be divided into two categories, namely, focusing on functional integration process type biochip (lab -on-a-chip), and a large amount of information can be obtained microarray type wafer (microarray). These two categories biochips have their own characteristics, and can be subdivided into several different types and applications. In addition to the above dichotomy outside also actively in the development of integrated bio-chips, hoping to specimen preparation, processing, analysis and the results of the detection can be accomplished microarray biochip type on the same piece of the wafer is a wafer substrate neat fixed, arranging a large number of biological probes, through DNA-DNA hybridization reaction between proteins or specific binding for sample analysis or testing.
Is the use of nucleic acid molecules capable of complementary binding (A with T; G with C) as the basis of the detected features, it must first carry out studies on the detection of nucleic acid sequences of the subject matter, in order to design a specific period of nucleic acid sequences as a biological probe, again The nucleic acid probe design neatly arranged, fixed in a wafer substrate, complete wafer production. Specimen obtained in the extraction of nucleic acid treated, after calibration, the hybridization reaction on the wafer through fluorescence method or chromogenic detection reaction signal to complete the line sample analysis or testing. Gene chip according to the length of nucleic acid probe may be subdivided into, chemically synthesized nucleic acid sequence with a short oligonucleotide microarray chips (oligonucleotides microarray), and having a complementary nucleic acid arrays wafer long nucleic acid sequences (cDNA microarray) two categories.
In situ synthesis on a wafer direct biosynthesis or chemical synthesis and then fixed on the wafer, and its length is usually between 10 to 50 nucleotides (nucleotide), applied to the detection and analysis (detection), the sequence analysis (sequencing), single-point gene polymorphism analysis (SNPs), genotype analysis (genotyping) and gene expression analysis (expression) and the like.
DNA derived from the organism or mRNA reverse transcribed into cDNA preparation and then the resulting PCR, the length of nucleic acids is usually 500 or more, the application to gene expression analysis-based.