ReadyMade Random Hexamers (randomers) are oligonucleotides composed of all possible sequences for a given length. As the coupling efficiency for each individual phosphoramidite is slightly different, a special blend of all 4 bases at different molar ratios is used to achieve an even nucleotide representation. The batch is then tested by synthesizing test randomer oligos and confirming base composition by enzymatic degradation and HPLC. 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]. You can use random sequence oligonucleotides to identify 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.