Assay Defender®

Total HAMA and Interference Blocker.

Assay Defender® is a ready-to-use sample dilution buffer that reduces multiple types of interference.  It is ideal for immunoassays with biological samples from humans and animals in which interference caused by HAMA (human anti-mouse antibodies), AAA (anti-animal antibodies) or other high-affinity antibodies can occur.

Assay Defender® reduces interference caused by:

• HAMA 
• Rheumatoid factors
• Nonspecific binding
• Cross-reactivities 
• Matrix effects

While ordinary HAMA blockers only work against interference caused by HAMA and other interfering antibodies, Assay Defender® eliminates interference from all sources.  This elimination optimizes the assay and helps prevent false positive or false negative results.

With its multiple functions as a diluent and optimizer, Assay Defender® prevents time and cost-intensive optimization steps such as HAMA blocker selection, extended titration experiments or addressing each interference source individually. 

When using Assay Defender®, calibrators must be diluted in this buffer. Dilution in Assay Defender® can be 1:2 or higher. A useful dilution factor for most applications is 1:10 (1 part specimen + 9 parts Assay Defender®). 

Assay Defender® vs. LowCross-Buffer®

Both Assay Defender® and LowCross-Buffer® contain the special "LowCross® effect" that allows them to prevent interference based on low and medium affinity binding. Interference from high affinity antibodies, however, can only be eliminated by Assay Defender®. Additionally, there are applications where LowCross Buffer may be the more appropriate choice.  Learn more about the differences between Assay Defender® and LowCross-Buffer®.