Vapor-Lock (50ml)

A hydrophobic, low-viscosity PCR sealing medium from QIAGEN designed for use as a reaction overlay. The product is a synthetic, high-molecular-weight polymer that is colorless, odorless, and nonhazardous, with no known contaminants including DNA, RNA, enzymes, metals, salts, or other trace elements. No autofluorescence has been detected spanning ultraviolet to infra-red, with excitation at 36–680 nm and emission at 460–712 nm.

Key physical properties include a viscosity of ≥5 centistoke, vapor pressure <1 mm Hg, boiling point >120°C, flash point <125°C, and solubility <100 ppb. Applied as a PCR overlay, the medium forms a barrier that prevents evaporation during thermal cycling, eliminating the need for tube caps and accelerating reaction setup. In experiments comparing C_T values, similar results were obtained from reactions in capped tubes compared to reactions overlaid with the medium in uncapped tubes. The product has been successfully used to ensure amplification for reaction volumes as low as 5 µl.

Its low viscosity and low specific gravity allow aqueous droplets over approximately 1 µl to drop easily through the overlay into the aqueous sample beneath. Unlike mineral oil, the product does not contaminate or inhibit PCR, and its background fluorescence is less than one fluorescence unit. It is fully compatible with the QIAgility instrument for high-precision, automated reaction setup and is highly suited for use with the Rotor-Gene Q cycler, making it appropriate for PCR and high-resolution melting (HRM) applications, including quantitative real-time PCR.