Using the infrared detection increase SNR by 3-5 fold of nitrocellulose colorimetric assay-labeled protein microarrays.

Protein arrays are widely used to measure protein expression in biological samples. One of the principal challenges on protein array technologies is to keep protein activity intact while immobilising proteins from complex samples. Nitrocellulose and PDVF membranes are known due to their ability of fixing proteins while keeping their structure and properties intact. Nitrocellulose supports has been used for long time in western blot and dot blot techniques.

Protein detection methods are basically the same as those used in western blot and dot blot techniques. They can be either colorimetric, luminescence or fluorescence detection. From them, colorimetric assays are very easy to perform and very robust across a broad spectrum of users, while fluorescence detection seems to be the more sensitive method with a higher dynamique range. Unfortunately, nitrocellulose supports give strong fluorescence leading the use of fluorescence detection almost impossible at the classical 532nm or 635nm wavelengths. Here we demonstrate that using infrared fluorescence detection it is possible to increase the SNR ratio from colorimetric-labelled protein arrays. The SNR increase is mainly due to a strong diminution of the background levels.  


Adriana Lagraulet1, Mark McQuain2

  • 1 Innopsys, Parc Activestre 31300 Carbonne - France
  • 2 Microarrays Inc., Huntsville, AL



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