Custom miRCURY LNA Detection Probe (1)

From QIAGEN, these custom probes use LNA (locked nucleic acid) enhancement for ultra-sensitive and specific in situ hybridization (ISH) of microRNAs. They enable specific detection of novel miRNAs, miRNAs not covered by predesigned miRCURY LNA miRNA Detection Probes, or other short non-coding RNA sequences, and can also serve as valuable controls in ISH experiments.

Each probe is custom-designed by QIAGEN technical support scientists, applying the same design rules used for the company's predesigned miRNA detection probes. Mismatch negative-control probes can be supplied that differ from the target by 1–3 nucleotides, with the number of mismatches and LNA positions chosen by the design team to bring the Tm value close to that of the target probe; when run on serial sections with the same ISH protocol, these mismatch controls should give little or no staining. Alternative positive-control probes targeting slightly different regions of the same sequence can also be produced, as can loop-directed probes that bind the loop sequence of the precursor miRNA to help rule out non-specific cross-hybridization (the expression level of the pre-miRNA being likely lower than that of the mature miRNA).

Designs are illustrated in published examples, including Nielsen et al. (2011), Clin Exp Metastasis 28 (1):27–38 (PMID: 21069438), and Rask et al. (2011), APMIS 119 (10):663-73 (PMID: 21917003), which show a custom mismatch negative control and target-specific positive-control probes (including a loop-directed probe) for miR-21, with binding sites displayed for four probes: a full-length 22-mer, a 17-mer, a 15-mer, and a loop-sequence-specific probe.