Quantitative detection of DNA

Application Note #117

Langmuir-blodgett

 "Quantification of single stranded oligonucleotides"

Compilation of the sensograms from several different injections (upper graph)

dNA assays can be applied for detecting genetic material in order to detect genetic disorders, mutations, gene transfection or species from a large variety of samples. By assaying specific single stranded oligonucleotides of over 20 nucleotides in length, it is possible to detect and quantify unique gene sequences from large amounts of genetic material.

27-unit oligonucleotide was self adsorbed onto a standard gold sensing surface. Non-specific binding was minimized using a (2-hydroxyethyl)-α-lipoamide molecule, which was self adsorbed onto the surface. Sample of PCR-amplified single stranded dNA having complementary sequence to the self adsorbed probes were tested against non-complementary dNA of same lenght and bovine serum albumin (BSA).

The measurements were performed in the fixed angle mode of SPR Navi™ 200. The sensitivity and specificity is compared to assay from literature performed wiht Biacore and shows identical detection limits. The SPR Navi™ performed well over a wide range of concentrations (0.1 nM to 1000 nM) and can be seen in the exponential fit. Single-site interactions are confirmed by an excellent compliance with the one-to-one Langmuir exponential fit. Non-complementary dNA and BSA of 1000 nM concentration was not detectable after buffer rinsing.

Recommended instrument for this application:

200_otso_small.jpg 210_vasa_small.jpg 220A_naali_small.jpg
420_ilves_small.jpg

                       green-tick.png  green-tick.png  green-tick.png 

Further reading

  • See also how faster interaction studies are done using KineticTitration
    in AN#155!
  • Do you want to see how MP-SPR instruments work? Click here.

  • Do you want to see MP-SPR instruments comparison? Click here.

  • Here are a few publications you can have a look at.

DOWNLOAD APPLICATION NOTE IN PDF


Back to all Application Notes