Virus Purification Using Protamine Sulfate Precipitation

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Solution Overview

Problem

Current methods for purifying viruses for vaccine production face challenges in removing host cell DNA and non-infectious virus particles, which can affect the safety and efficacy of vaccines.

Innovation Solution

The use of protamine sulfate to precipitate impurities from a virus harvest, followed by sucrose density gradient centrifugation to enrich infectious virus particles, provides a streamlined and effective purification process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional virus purification methods are used, then virus particles can be separated, but host cell DNA and non-infectious virus particles remain as contaminants

Engineering Contradiction:

Improvepurification qualityVSAvoidcontaminant levels

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces protamine sulfate as an intermediary substance that selectively binds to host cell DNA and non-infectious virus particles. This mediator enables the removal of contaminants without directly acting on the infectious virus particles, thereby achieving high purification quality while eliminating harmful factors.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes changes in physical and chemical parameters during sucrose density gradient centrifugation. By varying the density gradient and centrifugal force, the method separates virus particles based on their infectious status and density characteristics, achieving effective purification.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If multiple purification steps are implemented to remove contaminants, then purification quality improves, but process complexity increases

Engineering Contradiction:

Improvepurification qualityVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines protamine sulfate treatment and sucrose density gradient centrifugation into an integrated purification workflow. By merging the chemical treatment step with the physical separation step, the method achieves high purification quality while maintaining relatively simple process complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs protamine sulfate that performs multiple functions: it binds to host cell DNA, aggregates non-infectious virus particles, and facilitates their removal during centrifugation. This multi-functional approach reduces the need for multiple separate purification steps.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method significantly reduces residual host cell DNA and non-infectious virus particles, resulting in highly purified infectious virus preparations suitable for vaccine production.

Implementation Method 1

reducing impurities from the crude harvest (a) by precipitation with an agent comprising a protamine salt, preferably a protamine sulphate

Methodology Applied

Scientific EffectPrecipitation: Precipitation

Implementation Method 2

Protamine was originally isolated from the sperm of salmon and other species of fish but is now produced primarily through recombinant biotechnology. It is a highly cationic peptide that binds to negatively charged molecules such as nucleic acids to form a stable ion pair.

Methodology Applied

Scientific EffectIon pairing:

Implementation Method 3

further purifying the virus preparation (b) by method or methods selecting for size of the virus particles, such as e.g. a sucrose density gradient centrifugation to obtain a virus preparation (c) comprising the infectious virus particles

Methodology Applied

Scientific EffectDensity gradient centrifugation: Density Gradient