Oligonucleotide microarray

Many formats of DNA arrays are currently available in today s market. These formats include microarrays, oligonucleotide arrays, macroarrays, and microelectronic arrays. Choice of usage of any one of these formats would be very much dependent on the users research applications and budget. The different array formats can be differentiated by the... 

There are two main types of microarrays oligonucleotide microarrays and two-channel microarrays. An overview of the concepts behind the two types of microarrays can be found in Module 36 of the DNA from the Beginning tutorial. Two-channel microarrays were invented by Pat Brown in the mid 1990s. Institutions and researchers can purchase robotic machines in order to design and make their own two-channel microarrays. 

There are two formats of microarray oligonucleotide chips contain short (less than 60) nucleotides synthesized in situ on the solid support (1,2) and spotted DNA arrays where nucleic acids are robotically spotted onto a glass substrate (3). PCR product or plasmid DNA in 96/384-well format is transferred by specially engineered tips to multiple glass slides then dried and fixed to the glass substrate. 

Kasamatsu A, Endo Y, Uzawa K, Nakashima D, Koike H, Hashitani S, et al. Identification of candidate genes associated with salivary adenoid cystic carcinomas using combined comparative genomic hybridization and oligonucleotide microarray analyses. Int J Biochem Cell Biol 2005 37 1869-80. 

Kane MD et al. Assessment of the sensitivity and specificity of oligonucleotide [50mer) microarrays. Nucleic Acids Res 2000 28 4552-4557. 

Hughes TR et al. Expression profiling using microarrays fabricated by an inkjet oligonucleotide synthesiser. Nature Biotechnol 2001 19 342-347. 

In contrast to high density arrays low density arrays are made by deposition of pre-synthesized oligonucleotides or proteins on activated surfaces. There are several printing techniques for fabricating microarrays Non-contact biochip arrayers, commonly based on the piezoelectric effect, can apply controlled sub-nanoliter probe volumes to pre-specified locations on the chip surface. Due to the fact that the dispenser does not touch the surface, a non-contact arrayer provides low risk of contamination and is most suitable for printing on soft materials such as hydrogels. 

Y. Belosludtsev, B. Iverson, S. Lemeshko, R. Eggers, R. Wiese, S. Lee, T. Powdrill, and M. Hogan, DNA microarrays based on noncovalent oligonucleotide attachment and hybridization in two dimensions. Anal. Biochem. 292, 250—256 (2001). 

Urakawa H, Noble PA, El-Fantroussi S, Kelly JJ, Stahi DA (2002) Single base pair discrimination of terminal mismatches by using oligonucleotide microarrays and neutral network analyses. Appl Environ Microbiol 68 235-244... 

Yuen, T., et al., Accuracy and calibration of commercial oligonucleotide and custom cDNA microarrays, Nucleic Acids Res., 30, e48, 2002. 

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