Alternative Block ELISA Blocking Buffer

1. Allow product to equilibrate to room temperature (25°C) prior to use., 2. Add 100 µL to each Well. When reacting with peroxidase, a soluble blue reaction product develops that can be read at 370 nm or in a range of 620-650 nm. The reaction product is stable for 1 hour., 3. The reaction can be stopped using an appropriate stop solution, such as Stop Solution for TMB Substrates (STOPT), for endpoint assays. STOPT changes the chromogen from blue to yellow and the absorbance to 450 nm. For best results, sample absorbance should be monitored and read before values exceed 2.0 OD units. STOPT can increase the absorbance up to 3-fold, so the reaction should be stopped when absorbance values reach approximately 0.7 OD units.

Alternative Block is a protein-free, detergent-free ELISA blocking buffer. This unique blocking buffer contains a heterogeneous mixture of proprietary blockers and synthetic stabilizers that block the uncoated regions of the microtiter plate without the use of conventional cross-reactive protein additives or detergents. This buffer is best for most immunoassays, including antibody-sandwich ELISA, competitive assays, and peptide and protein antigen-down ELISA., , Alternative Block’s all-synthetic heterogenous mixture of blocking agents minimizes non-specific binding interactions during the immunoassay process to reduce background noise. Alternative Block provides a microhydrated environment to stabilize the coated protein during long-term storage for improved retention of antigen epitope and antibody binding activity. When preparing batches for storage, an antimicrobial agent allows for stable room temperature blocking and long-term refrigerated storage of dried plates.