There is no singular root cause for false positives. In fact, there can be multiple factors at play depending on your specific application. The problem should be approached systematically changing one parameter at a time allowing a process of elimination. Following is a proposed sequence of questions:
- Is the problem due to charge? Varying the pH (from 5–11) will show if a positive charge is occurring and attracting the gold to the capture line.
- Is the problem due to hydrophobicity? This can occur in the solid phase, capture line, or gold conjugate. Varying surfactant concentrations will give an idea as to whether the problem is due to hydrophobicity problems.
- Is the problem attraction between the gold and SH (thiol group)? This could be from cysteine present in the capture line.
This short informative video outlines insights and provides simple solutions for resolving false positive issues.
If you have questions related to this content or other filtration concepts or how they apply to your specific application, please contact us.
Author bio
Jacques Hestres, Product Manager for Media – Membrane
Focusing primarily in Medical OEM applications. Throughout his over 25 years at the company, Jacques has held various positions in Customer and Technical Service, Operations Planning, and Product Management. This experience has given him the knowledge of the products, the manufacturing processes used to produce these materials, and an understanding of applications where these are used. Jacques holds a Bachelor’s of Science Degree in Biology from the University of Puerto Rico.
Joseph Vickers - Portfolio Lead, Membrane and Media
A Global Portfolio Leader at Cytiva, responsible for the Membranes and Media portfolio. He has previous experience in global marketing and operations, holding an MEng in Chemical Engineering from the University of Surrey.
Antoine Pozniak - Product Manager Media - Membrane
Antoine has held various roles in sales and marketing throughout his 4-year career in the medical device industry. Throughout those 4 years he has worked with Key Opinion Leaders and developed commercial and technical knowledge. Antoine holds an MBA from Rice University and Bachelor of Arts/Sciences in Interdisciplinary Social Sciences from The University of South Florida.