Locked Nucleic Acid (LNA®) was first described by Wengel and co-workers in 1998 as a novel class of conformationally restricted oligonucleotide analogues. LNA® is a bicyclic nucleic acid where a ribonucleoside is linked between the 2’-oxygen and the 4’-carbon atoms with a methylene unit.
| Name |
Synthesis scale |
Purification |
Reference |
EUR |
|
| 5' and Internal LNA® incorporations |
40 nmol |
RP-Cartridge |
OL-LN20-01 |
15.00 |
|
| 5' and Internal LNA® incorporations |
0.2 µmol |
RP-Cartridge |
OL-LN-21-01 |
20.00 |
|
| 5' and Internal LNA® incorporations |
1.0 µmol |
RP-Cartridge |
OL-LN-22-01 |
25.00 |
|
| 3' LNA® incorporations |
40 nmol |
RP-Cartridge |
OL-LN20-03 |
25.00 |
|
| 3' LNA® incorporations |
0.2 µmol |
RP-Cartridge |
OL-LN21-03 |
30.00 |
|
| 3' LNA® incorporations |
1.0 µmol |
RP-Cartridge |
OL_LN22-03 |
35.00 |
|
Price per modificationQuality Control MALDI-TOF Mass Spectrometry Delivery times 2-14 bases: 5 Working days 15-39 bases: 5 Working days 40-80 bases: 7-8 Working days > 80 bases: 10 Working days Packaging Lyophilised Shipping conditions Room temperature Storage conditions -20 °C to –70 °C Oligonucleotides are stable in solution at 4 °C for up to 2 weeks. Properly reconstituted material stored at -20 °C should be stable for at least 6 months. Lyophilized DNA (when kept at -20 °C) in a nuclease-free environment should be stable for years.
By changing the conformation of the helix and by increasing the stability of the duplex, the integration of LNA® bases into your oligo sequence opens new perspectives to your DNA affinity based studies. For instance, LNA® may be used to improve techniques requiring high affinity probes as specific as possible like SNP detection, expression profiling, and in situ hybridization.
What does it look like?
LNA® is a bicyclic RNA analogue, in which the ribose moiety in the sugar-phosphate backbone is structurally constrained by a methylene bridge between the 2’-oxygen and the 4’-carbon atoms (Obika et al. 1997, Koskhin et al. 1998, Singh et al. 1998).
The pre-organized conformation of the LNA® nucleoside was predicted to be a N-type sugar puckering (Fig.1), characteristic for A-type double helices, such as RNA-RNA duplexes. This assumption has been confirmed by NMR solution studies and X-ray crystallographic analysis. The LNA® oligonucleotide conformational structure, examining both sugar puckering and oligonucleotide backbone, has been determined by two-dimensional NMR analysis. The preliminary LNA® nucleoside spectra demonstrated the fixed N-type conformation of LNA® (Koskhin et al. 1998, Singh et al. 1998). Subsequent NMR studies have analyzed the structure of LNA® oligonucleotides, either as single stranded oligonucleotides or hybridized to complementary DNA and RNA (Nielsen et al. 1999, Bondensgaard et al. 2000, Nielsen et al. 2000, Petersen et al. 2000, Petersen et al. 2002). The spectra confirmed the locked N-type conformation of the LNA® sugar pucker, but also revealed that LNA® monomers are able to twist the neighbouring, unmodified nucleotides from an S-type towards an N-type conformation in DNA/LNA® mixmer oligos and LNA®-containing duplexes.
The fixed N-type (3’-endo) conformation of the LNA® nucleoside, together with enhanced stacking of the nucleobases results in higher thermal stability of LNA®-containing duplexes.
The structural consequence
The integration of LNA® bases into probes changes the conformation of the duplex when the annealing with DNA bases occurs. The integration of LNA® moieties on every third position changes the structure of the double helix from the B to the A type. This conformation allows a much better stacking and then a higher stability.
An increased Tm: the direct advantage
By increasing the stability of the duplex, the integration of LNA® monomers into the oligonucleotide sequence consequently increases the Tm of the duplex.
This characteristic allows a reduction in the size of the probe and, therefore, increases its specificity.
Each LNA® incorporation increases the Tm of the duplex. The following table shows the average Tm increase for DNA or RNA duplex with oligos containing either LNA®, RNA or PNA moieties.
Aplications overview
LNA® should be used in any hybridization assay, which requires high specificity and/or reproducibility. LNA® may be used to enhance: - Real-Time qPCR probes
- in situ hybridization probes
- Primers for single, multiplex and allele specific PCR
- Capture probes for SNP genotyping
- Capture probes for expression analysis
- Probes to monitor exon skipping
- Improvement of SNP discrimination
The LNA® modification perfectly suits to SNP detection
First, the reduction of the size of the probe increases the impact of one mismatch in the stability of the duplex probe/target.
Also, by designing probes with an LNA® moiety in front of the variable position it becomes possible to discriminate very efficiently the allelic variations. The mismatch would avoid the A helix structure stabilisation and then decrease the Tm considerably. This modification not only increases the specificity of the probe but also its power of discrimination.
Advantages
- Increased affinity
LNA® increases the thermal stability of duplexes due to its RNA-like structure. LNA®:LNA® duplex formation constitutes the most stable Watson-Crick base pairing system. - Better Tm modulation
Depending on their position along the sequence, LNA® bases provide a means to reach the desired Tm level without losing specificity. Introduction of LNA® allows for shorter probes while maintaining the same Tm. - Increased specificity
LNA® enhances hybridization perfomance relative to native DNA, RNA or phosphorothioate. LNA® lowers experimental error rates due to better mismatch discrimination. LNA® improves signal-to-noise ratio. - Enzyme compatibility
LNA® shows increased resistance to certain exo- and endonucleases thus leading to biostability making this modification perfect for in vivo antisense applications. DNA-LNA® chimeras readily activate RNase H. LNA® acts as a substrate for standard molecular biology enzymes: T4 PNK, T4 DNA ligase, DNA polymerases. - Simplicity
LNA® behaves like DNA, so it is easily transferable to DNA-based assays. Moreover LNA® can also be coupled to RNA bases. LNA® is highly soluble in water. LNA® complies with almost all oligonucleotide synthesis and analysis methods (QC, purification, etc) and exhibits the same salt dependence as DNA and RNA.
Product description
Eurogentec offers a full range of products and services to deliver the LNA® based probes for your application.
All four LNA® bases (LNA®-A, LNA®-T, LNA®-G and 5-Me-LNA®-C) can be mixed with DNA, RNA as well as other nucleic acid analogues using standard phosphoramidite DNA synthesis chemistry. Therefore, LNA® oligonucleotides can be tagged with e.g. aminolinkers, biotin, fluorophores, etc. Thus a very high degree of freedom in the design of primers and probes exists.
The oligonucleotides containing LNA® bases are desalted, deprotected, chromatography purified and controlled by MALDI-TOF Mass Spectrometry.
Legal notices For Research Use only
LeafletsProduct citationsLEGENDRE D. et al., "Engineering a regulatable enzyme for homogeneous immunoassays", Nature Biotechnology, vol. 17, n° 1, p.67-72, 1 January 1999 MOMENI P. et al., "Mutations in a new gene, encoding a zinc-finger protein, cause tricho-rhino-phalangeal syndrome type I", Nature Genetics, vol. 24, p. 71-74, 1 January 2000 PEREL Y. et al., "Galanin and galanin receptor expression in neuroblastic tumours: correlation with their differentiation status", British Journal of Cancer, vol. 86, n° 1, p. 117-122, 7 January 2002 OSTERMANN G. et al., "JAM-1 is a ligand of the 2 integrin LFA-1 involved in transendothelial migration of leukocytes", Nature Immunology, vol. 3, n° 2, p.151-158, 1 February 2002 GOMEZ D. et al., "Interaction of Telomestatin with the Telomeric Single-strand Overhang", Journal of Biological Chemistry, vol. 279, n° 40, p. 41487-41494, October 2004 RZEM et al., "A gene encoding a putative FAD-dependent L-2-hydroxyglutarate dehydrogenase is mutated in L-2-hydroxyglutaric aciduria", PNAS, vol. 101, n° 48, 16849-16854, November 2004 SU T.-J. et al., "DNA bending by M.EcoKI methyltransferase is coupled to nucleotide flipping", Nucleic Acids Research, vol. 33, n° 10, 3235-3244, June 2005
VAN DER STEEGE G. et al., "Persistent failures in gene repair", Nature Biotechnology, n° 19, p. 305-306, April 2001 ISCHENKO A.A. et al., "Alternative nucleotide incision repair pathway for oxidative DNA damage", Nature, n° 415, p. 183-187, 10 January 2002 KRISTENSEN A. et al., "Detection of Mutations in Exon 8 of TP53 by Temperature Gradient 96-Capillary Array Electrophoresis", Biotechniques, n° 33, p. 650-653, September 2002 VANDEN ABEELE F. et al., "Store-operated Ca2+ Current in Prostate Cancer Epithelial Cells", Journal of Biological Chemistry, vol. 278, n° 17, p. 15381-15389, April 2003 GROS L. et al., "Hijacking of the Human Alkyl-N-purine-DNA Glycosylase by 3,N4-Ethenocytosine, a Lipid Peroxidation-induced DNA Adduct", Journal of Biological Chemistry, vol. 279, n° 17, p. 17723-17730, April 2004 MORGAN M. et al., "YY1 Regulates the Neural Crest-associated slug Gene in Xenopus laevis", Journal of Biological Chemistry, vol. 279, n° 45, p. 46826-46826, November 2004 DI GIUSTO D. et al., "Construction, Stability, and Activity of Multivalent Circular Anticoagulant Aptamers", Journal of Biological Chemistry, vol. 279, n° 45, p. 46483-46489, November 2004
KALISH J. M. et al., "Triplex-induced recombination and repair in the pyrimidine motif", Nucleic Acids Research, vol. 33, n° 11, 3492-3502, June 2005 DECOUSSER J.-W. et al., "New Real-Time PCR Assay Using Locked Nucleic Acid Probes To Assess Prevalence of ParC Mutations in Fluoroquinolone-Susceptible Streptococcus pneumoniae Isolates from France", Antimicrobial Agents and Chemotherapy, p. 1594-1598, Vol. 50, No. 4, April 2006
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