Sources: Nature; Science JONATHAN CORUM/THE NEW YORK TIMES Double-stranded RNA (dsRNA) Rare outside of viruses, long double strands of RNA are treated as hostile by the body.
Double-stranded probes were made by annealing oligonucleotides into double strands and labelled with T4 polynucleotide kinase (Gel Shift Assay Core System; Promega) in the presence of [γ-32P]dATP.
The sequence of the hairpin probe was designed and optimized for hybridizing with single-stranded DNAzyme but not with DNAzyme-substrate double strands.
The single-stranded plasmids in the flow-through were converted to double strands using the Sequenase DNA polymerase (Amersham, Piscataway, NJ, USA).
Substrates were 21-nucleotides long and either single-stranded or annealed to a complementary oligonucleotide to create blunt double strands.
Single-stranded phagemids were purified by using HAP chromatography and converted to double strands by using SEQUENASE v2.0 DNA polymerase (USB, Staufen, Germany) and M13 primer.
The denaturation step separates the double strands of DNA; this model assumes denaturation is complete.
Double strands DNA with multiple branched arms (mdsDNA) was formed by mHCR.
The breakthrough came partly through starting the sequencing with single strands of DNA, as opposed to the usual approach of using double strands.
If you took all the DNA in human chromosomes, unraveled the double strands and strung them end to end, how far would it reach?
But it now appears that tiny double strands of RNA, introduced into lab-grown cells or animals, can quickly and efficiently turn off any given gene.
