Category: Super G

Optimized Blocking Of Porous Nitrocellulose Films For Sensitive Protein Microarrays

Michael A. Shultz, Aki Ohdera, Jason MacManiman, Charles M. McGrath. Grace Bio-Labs, Inc.   ABSTRACT Super G Blocking Buffer was developed to produce low backgrounds in assays using nitrocellulose film-slides.  Using this blocking reagent in combination with ONCYTE® SuperNOVA Film-slides, we achieved an order of magnitude greater sensitivity in a cytokine microarray assay than with … Continued

Inclusion of Super G in All Steps of Protein Arrays Improves S/N

Blocking reagents are used to reduce non-specific protein binding in immunoassays, significantly improving results in terms of Signal-to-Noise ratio. Typically the blocking reagent is added prior to addition of the primary detection antibody.In this study we asked the question as to whether addition of the blocking reagent to other steps in a protein array assay … Continued

Optimizing Reverse Phase Protein Array Assays

Components of Reverse-Phase Protein Array (RPPA) methods and their impact on the overall performance of this assay were presented at the 2nd annual RPPA Conference in Edinburgh, Scotland on November 12.  Entire presentation can be viewed here.  View poster here. View here for information regarding our RPPA Assay System Selecting Surfaces, Reagents, and Detection Methods … Continued

Preserving Protein Immuno-Reactivity

Microarrays deposited onto solid supports are robust platforms for performing antibody capture and antigen detection assays.  Among various substrates, thin film porous nitrocellulose cast on glass surfaces has excelled in the field of proteomics since its invention by scientists at Grace Bio-Labs (McGrath, CM, Grudzien, J and A. Levine. Cell Vision 2:499-509, 1995). The irregular 3-dimensional … Continued

From Western Blot to Protein Array with Super G Blocking Buffer

Results obtained from Western blots can be highly variable and dependent not only on the specific antigen/antibody pairs used, but also on other reagents in the protocol such as blocking buffer. Not surprisingly, no one “universal” blocking reagent works well with all proteins. Thus choice of blocking reagent should be assessed for optimal results and having … Continued

Protein Staining Nitrocellulose using SYPRO® Ruby

Reverse phase protein arrays (RPPA) offer great promise for the identification and analysis of critical biomarkers for disease states in patient samples and for high-throughput drug screening using cultured cell systems.  Porous nitrocellulose (NC) film slides continue to be the preferred substrate for RPPA due to their high protein binding capacity and many functional advantages. … Continued

Super G: Super Blocking and Signal-to-Noise for ONCYTE Film Slides

Fluorescence detection is a preferred method for many quantitative protein microarray assays in research and diagnostic applications due to its excellent sensitivity and potential for multiplexing. Use of multiplexed fluorescence-based assays on porous nitrocellulose though has been hampered by high backgrounds at shorter excitation wavelengths (such as the 532 nm fluorescence channel).  To maximize the … Continued

Super G Blocking Reagent for Western Blots

Although Super G blocking reagent was developed and optimized for fluorescent endpoint detection on nitrocellulose film slides, we have found that it is also an effective blocker for Western blot applications. Data presented below illustrate the effectiveness of Super G blocking reagent in typical Western blot experiments using nitrocellulose membranes by reducing background staining and … Continued

Multiplex Protein Arrays with Quantum Dots

Multiplexed protein arrays offer significant advantages for diagnostics over monoplex assays such as ELISA’s. For multiplex detection, fluorescence is the label of choice, offering rapid and sensitive detection and large dynamic range in addition to the ability to separate signals from multiple fluors.While porous nitrocellulose (NC) film slides are an excellent substrate for protein arrays … Continued

Optimize Your Protein Array with Specially Formulated Arraying Buffer

The buffer used for spotting proteins for protein arrays is a critical factor in obtaining reliable and consistent results. Most important impact is on protein aggregation, which can affect spot morphology,  and protein binding to the substrate. Grace Bio-Labs has developed a Protein Arraying Buffer designed to work with our ONCYTE® porous nitrocellulose film slides for optimal … Continued

Once around the Block for Antibody Selection

Selecting the right antibody for your application is sometimes like buying a pair of shoes- you may have to try on a few to get the right fit. It turns out that you may also want to walk around the ‘block’—or blocking reagent, in this case, to get the right fit for your antibody.  We … Continued

Protein Microarrays on the Brink?

Microarray technology was first exploited with genomic analysis of DNA sequences.  This technology still forms a robust platform for biomarker discovery and comparative genomics. However, while genomics sheds light on the biological potential, a recent review in Science Signaling  points out that  “protein does the heavy lifting in the cell, and neither DNA nor RNA says much … Continued