The present invention relates to methods and kits for detecting in a sample the presence of a virus particle or a virus-like particle that has reverse transcriptase activity and methods for preparing a retroviral contaminant-free substance. An aspect of the present invention is a method for detecting the presence of a virus particle in a sample of a Virus-like Particle (VLP) drug substance comprising a step of performing PCR-based reverse transcriptase (PBRT) on a sample of the VLP drug substance that has been treated with a protease.

A method for producing reassortant influenza viruses is provided. Also provided are reassortant influenza viruses produced according to the method, as well as vaccines based on said reassortant influenza viruses.

A two-step chromatography purification scheme is described which selectively captures and isolates the genome-containing rAAV vector particles from the clarified, concentrated supernatant of a rAAV production cell culture. The process utilizes an affinity capture method performed at a high salt concentration followed by an anion exchange resin method performed at high pH to provide rAAV vector particles which are substantially free of rAAV intermediates.

A two-step chromatography purification scheme is described which selectively captures and isolates the genome-containing rAAV vector particles from the clarified, concentrated supernatant of a rAAV production cell culture. The process utilizes an affinity capture method performed at a high salt concentration followed by an anion exchange resin method performed at high pH to provide rAAV vector particles which are substantially free of rAAV intermediates.

The present invention provides Factor IX fusion proteins with higher specific activity and a longer useful clotting function relative to wild type or non-modified Factor IX protein.

Described herein are Zika virus vaccines and compositions and methods of producing and administering said vaccines to subjects in need thereof.

Described herein are Zika virus vaccines and compositions and methods of producing and administering said vaccines to subjects in need thereof.

The present invention is directed to viral vectors and methods of their production and use.

The present invention is directed to viral vectors and methods of their production and use.

The present invention provides Factor IX fusion proteins with higher specific activity and a longer useful clotting function relative to wild type or non-modified Factor IX protein.