Randomers are oligonucleotides composed of all possible sequences for a given length. The use of randomers began in the early 1980s when random hexamers were employed in radiolabeling DNA probes [1,2]. A later application was the use of random sequence primers to detect random amplified polymorphisms (RAPDs) [3,4].

Random sequence oligonucleotides are currently being used to detect single nucleotide polymorphisms (SNPs) as well as small scale chromosome events, primarily insertions or deletions [5,6]. Comparative genomic hybridization (CGH) has been developed to elucidate genome-wide sequence copy-number variation (CNV) between different genomes, such as the differential amplification or deletion of genetic regions between tumor DNA and normal DNA from neighboring unaffected tissue [7–10]. These applications demand that the oligonucleotides have consistent base composition and minimal lot-to-lot variation.

IDT ReadyMade Randomers are synthesized using an N-base phosphoramidite mixture that is carefully prepared in bulk to ensure that equal base representation is achieved. The batch is then tested by making test randomer oligos and confirming actual base composition by enzymatic degradation and HPLC. ReadyMade Randomers are delivered dried down.

References

1. Feinberg AP and Vogelstein B (1993) A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity.  Anal Biochem, 132:6–13.
2. Feinberg AP and Vogelstein B (1984) A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity. Addendum.  Anal Biochem, 137:266–7.
3. Williams JG, Kubelik AR, et al. (1990) DNA polymorphisms amplified by arbitrary primers are useful as genetic markers.  Nucleic Acids Res, 18:6531–6535.
4. Forrest AK, Jarvest RL, et al. (2000) Aminoalkyl adenylate and aminoacyl sulfamate intermediate analogues differing greatly in affinity for their cognate Staphylococcus aureus aminoacyl tRNA synthetases. Bioorg Med Chem Lett, 10:1871–1874.
5. Houldsworth J and Chaganti R (1994) Comparative genomic hybridization: an overview. Am J Pathol 145:1253–1260.
6. Lichter P,  Bentz M, and Joos S (1995) Detection of chromosomal aberrations by means of molecular cytogenetics: painting of chromosomes and chromosomal subregions and comparative genomic hybridization. Methods Enzymol, 254:334–359.
7. Kallioniemi A, Kallioniemi O-P, et al. (1992) Comparative genomic hybridization for molecular cytogenetic analysis of solid tumors. Science, 258:818–821.
8. Pinkel D, Segraves R, et al. (1998) High resolution analysis of DNA copy number variation using comparative genomic hybridization to microarrays. Nat Genet 20:207–211.
9. Emanuel BS and Saitta SC (2007) From microscopes to microarrays: dissecting recurrent chromosomal rearrangements. Nat Rev Genet, 8(11):869–83.
10. Gresham D, Dunham MJ, and Botstein D (2008) Comparing whole genomes using DNA microarrays. Nat Rev Genet, 9(4):291–302 .