What is an OD-mL and why don you sell by gold weight or molarity?
OD-mL is short for Optical Density per milliliter. We believe this is the best way to sell our products because this is the only way to truly measure the concentration (number) of the gold nanoparticles you are purchasing. Before we ship the product we measure the optical density with our NIST traceable UV-VIS spectrophotometer. This analysis gives the exact number of gold nanoparticles per milliliter. When we see competitors selling their products by gold weight, we know that they are determining this property by the amount of gold used for production. Depending on the process, the amount of gold that is used versus the amount of gold that ultimately winds up as gold nanoparticles can vary 10-fold. (Usually always at the customer’s expense!!). If you’d like to know more about Optical Density – mL and how its used, please visit our info note at: Info Note 804: UV-VIS Nomenclature and Units Quantum Dots are purchased by molarity. We often are asked why we don’t sell ours by molarity too
