ELISA Blocking Buffers

Paramount to Reducing Background Noise and Attaining an Accurate Signal

Once the antibody or protein antigens have been properly adsorbed onto the ELISA/EIA plate, the next critical step in creating a reliable immunoassay is the blocking of the plate. This key is:

• Preventing nonspecific binding 
• Reducing ELISA background signal 
• Blocking nonspecific binding to adsorbed proteins 
• Stabilizing proteins adsorbed to plate for better interactions 

Neuromics's ELISA Blocking Buffer formulations reduce nonspecific binding of sample and assay components to the ELISA well while stabilizing the coated protein. Six formulations offer significant benefits to different assay situations. Browse the product selections below, or order our Blocking Buffer Optimization Pack to try three formulations at an economical rate.

Proud Distributor of RayBiotech's Antibody Arrays and ELISAs

Pioneer and Market Leader

I am pleased to announce we are a distribution partner for RayBiotech. The solutions we offer include Antibody Arrays and ELISA Kits. With these additions, you now have many options for the either the qualitative, semi-quantitative or quantitative measurement of protein expression. From single antibody pair ELISAs to multiplexed arrays. The arrays enable you to simultaneously analyze up to 80 cytokine, inflammatory response, growth factor or angiogenesis related proteins.

In this posting, I focus on our new C-Series Antibody Array Kits. The kits utilize the sandwich immunoassay principle, wherein a panel of capture antibodies is printed on a nitrocellulose membrane solid support (usualy 2.5 cm x 3 cm). The array membranes are processed similarly to a Western blot (chemiluminescent readout). Signals are then visualized on x-ray film or a digital image, allowing densitometry data collection and calculation of fold-changes for each detected protein. The entire procedure can be completed in 1 day, and is simple enough to permit even the novice researcher to successfully collect data with very few pitfalls and little or no optimization.

They are proven and frequently published. You can now analyze the protein expression in you assays for a fraction of the cost of tradition methods. Here's an example: Simona Giorgini, Daniela Trisciuoglio, Chiara Gabellini, Marianna Desideri, Laura Castellini, Cristina Colarossi, Uwe Zangemeister-Wittke, Gabriella Zupi and Donatella Del Bufalo. Modulation of bcl-xL in Tumor Cells Regulates Angiogenesis through CXCL8 Expression. doi: 10.1158/1541-7786.MCR-07-0088. Mol Cancer Res August 2007 5; 7

Figure: bcl-xL overexpression in ADF glioblastoma and M14 melanoma cells increases CXCL8 expression. Image of membranes from a protein array. Membranes are probed with CM from the (A) glioblastoma control (AN8) and bcl-xL–overexpressing (AXL42 and AXL74) clones and (B) melanoma control (Mneo) and bcl-xL–overexpressing (MXL12 and MXL90) clones. In the negative control (NEG), the CM is replaced with an appropriate mock buffer according to array protocol. The intensity of protein signals for each membrane was compared with the relative positive signals by densitometric analysis. C. Schematic representation of proangiogenic factors that can be detected by the use of the membrane. The CXCL8, TGF-1β, TIMP1, TIMP2, and VEGF protein signals (two spots) are indicated by red, blue, yellow, violet, and green rectangles, respectively, in each image....The Human Angiogenesis Antibody Array I (RayBiotech. Inc.) was used according to the manufacturer's protocol to evaluate the secretion of 20 angiogenic factors into the CM of the different lines. A schematic representation of the proangiogenic factors that may be detected by the use of the array has been reported in the above figure. Membranes spotted in duplicate with antibodies against angiogenic factors were blocked with blocking buffer and then were incubated overnight with CM. Next, membranes were washed with wash buffer, incubated with biotin-conjugated antibodies against proangiogenic factors, washed with wash buffer, and incubated with horseradish peroxidase–conjugated streptavidin. The signals on the membranes were detected by chemiluminescence. Membranes, blocking and wash buffer, and antibodies against proangiogenic factors were all provided with the kit. The intensity of protein signal (two spots for each protein) was compared with the relative positive signals by densitometric analysis.

Here's an excellent video that provides more detail on Antibody Array Kit capabililities:

I will continue to post information on new addition with related pubs and data.

ELISA techniques and protocols

Power Point of ELISA Methods and Protocols(pps - 1.4M)
This teaching guide covers the three major types of ELISA: indirect, competitive, and sandwich. It integrates theory with practice, to help you understand what you are doing, and help you to do it!

Courtesy of our friends at Novus Biologicals.