Dual polarization interferometry

Dual polarization interferometry

Dual polarization interferometry (DPI) is an analytical technique that can probe molecular scale layers adsorbed to the surface of a waveguide by using the evanescent wave of a laser beam confined to the waveguide. Typically used to measure the conformational change in proteins or other biomolecules as they function (referred to as the conformation activity relationship).

DPI[1] focuses laser light into two waveguides. One of these functions as the "sensing" waveguide having an exposed surface while the second one functions to maintain a reference beam. A two-dimensional interference pattern is formed in the far field by combining the light passing through the two waveguides. The DPI technique rotates the polarization of the laser to alternately excite two polarization modes of the waveguides. Measurement of the interferogram for both polarizations allows both the refractive index and the thickness of the adsorbed layer to be calculated. The polarization can be switched rapidly, allowing real-time measurements of chemical reactions taking place on a chip surface in a flow-through system. These measurements can be used to infer conformational information about the molecular interactions taking place as the molecule size (from the layer thickness) and the fold density (from the RI) change. DPI is typically used to characterise biochemical interactions by quantifying any conformational change at the same time as measuring reaction rates, affinities and thermodynamics.

The technique is quantitative and real-time (10 Hz) with a dimensional resolution of 0.01 nm.[2]

A novel application for Dual Polarization Interferometry recently emerged where the intensity of light passing through the waveguide is extinguished in the presence of crystal growth. This has allowed the very earliest stages in protein crystal nucleation to be monitored.[3] The latest versions of Dual Polarization Interferometers also have the capability to quantify the order and disruption in birefringent thin films.[4] This has been used, for example, to study the formation of lipid bilayers and their interaction with membrane proteins.[5][6]

References

  1. ^ Cross, G; Reeves, AA; Brand, S; Popplewell, JF; Peel, LL; Swann, MJ; Freeman, NJ (2003). "A new quantitative optical biosensor for protein characterisation". Biosensors and Bioelectronics 19 (4): 383. doi:10.1016/S0956-5663(03)00203-3. PMID 14615097. 
  2. ^ Swann, MJ; Freeman, NJ; Cross, GH (2007). "Dual Polarization Interferometry: A Real-Time Optical Technique for Measuring (Bio)Molecular Orientation, Structure and Function at the Solid/Liquid Interface". In Marks, R.S; Lowe, C.R.; Cullen, D.C.; Weetall, H.H.; Karube, I.. Handbook of Biosensors and Biochips. Vol. 1. Wiley. pt. 4, ch. 33, pp. 549–568. ISBN 978-0-470-01905-4. 
  3. ^ Boudjemline, A; Clarke, DT; Freeman, NJ; Nicholson, JM; Jones, GR (2008). "Early stages of protein crystallization as revealed by emerging optical waveguide technology". Journal of Applied Crystallography 41: 523. doi:10.1107/S0021889808005098. 
  4. ^ Mashaghi, A; Swann, M; Popplewell, J; Textor, M; Reimhult, E (2008). "Optical Anisotropy of Supported Lipid Structures Probed by Waveguide Spectroscopy and Its Application to Study of Supported Lipid Bilayer Formation Kinetics". Analytical Chemistry 80 (10): 3666. doi:10.1021/ac800027s. PMID 18422336. 
  5. ^ Sanghera, N; Swann, MJ; Ronan, G; Pinheiro, TJ (2009). "Insight into early events in the aggregation of the prion protein on lipid membranes". Biochimica et Biophysica Acta 1788 (10): 2245–51. doi:10.1016/j.bbamem.2009.08.005. PMID 19703409. 
  6. ^ Lee, TH; Heng, C; Swann, MJ; Gehman, JD; Separovic, F; Aguilar, MI (2010). "Real-time quantitative analysis of lipid disordering by aurein 1.2 during membrane adsorption, destabilisation and lysis". Biochimica et Biophysica Acta 1798 (10): 1977–86. doi:10.1016/j.bbamem.2010.06.023. PMID 20599687. 

Further reading

  • Cross, GH; Ren, Y; Freeman, NJ (1999). "Young’s fringes from vertically integrated slab waveguides: Applications to humidity sensing". Journal of Applied Physics 86: 6483. Bibcode 1999JAP....86.6483C. doi:10.1063/1.371712. 
  • Cross, G (2003). "A new quantitative optical biosensor for protein characterisation". Biosensors and Bioelectronics 19: 383. doi:10.1016/S0956-5663(03)00203-3. PMID 14615097. 
  • Freeman, NJ; Peel, LL; Swann, MJ; Cross, GH; Reeves, A; Brand, S; Lu, JR (2004). "Real time, high resolution studies of protein adsorption and structure at the solid–liquid interface using dual polarization interferometry". Journal of Physics: Condensed Matter 16: S2493. Bibcode 2004JPCM...16S2493F. doi:10.1088/0953-8984/16/26/023. 
  • Khan, TR; Grandin, HM; Mashaghi, A; Textor, M; Reimhult, E; Reviakine, I (2008). "Lipid redistribution in phosphatidylserine-containing vesicles adsorbing on titania.". Biointerphases 3 (2): FA90. doi:10.1116/1.2912098. PMID 20408675. 

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Surface plasmon resonance — The excitation of surface plasmons by light is denoted as a surface plasmon resonance (SPR) for planar surfaces or localized surface plasmon resonance (LSPR) for nanometer sized metallic structures.This phenomenon is the basis of many standard… …   Wikipedia

  • Nucleic acid methods — For protein methods, see Protein methods. Nucleic acid methods are the techniques used to study nucleic acids (DNA and RNA). Purification Phenol chloroform extraction minicolumn purification RNA extraction Quantification Abundance in weight:… …   Wikipedia

  • Nanobiotechnology — Part of a series of articles on Nanotechnology …   Wikipedia

  • Green fluorescent protein — EGFP redirects here. EGFP may also refer to the ICAO airport code for Pembrey Airport. GFP ribbon diagram. From PDB 1EMA …   Wikipedia

  • Denaturation (biochemistry) — This egg s protein has undergone denaturation and loss of solubility, caused by the high rise of the temperature of the egg during the cooking process. Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and …   Wikipedia

  • Gel electrophoresis — apparatus – An agarose gel is placed in this buffer filled box and electrical field is applied via the power supply to the rear. The negative terminal is at the far end (black wire), so DNA migrates toward the camera. Classification… …   Wikipedia

  • Lipid — Structures of some common lipids. At the top are oleic acid[1] and cholesterol.[2] The middle structure is a triglyceride composed of oleoyl, stearoyl, and palmitoyl chains at …   Wikipedia

  • SDS-PAGE — PAGE redirects here. For other uses, see Page (disambiguation). Picture of an SDS PAGE. The molecular marker is in the left lane SDS PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis, describes a collection of related techniques… …   Wikipedia

  • Immunostaining — Micrograph of an immunostained section of a brain tumour. GFAP immunostain. Immunostaining is a general term in biochemistry that applies to any use of an antibody based method to detect a specific protein in a sample. The term immunostaining was …   Wikipedia

  • Immunoprecipitation — (IP) is the technique of precipitating a protein antigen out of solution using an antibody that specifically binds to that particular protein. This process can be used to isolate and concentrate a particular protein from a sample containing many… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”