Particle/PFU ratio

The particle/PFU ratio is a useful quantification in virology that reflects the ratio of virion particles to actually viable virus.

A virion is created when, after a cycle of replication inside a cell, a virus is able to re-form a physical capsid and bud extracellularly. Due to the many bottlenecks in viral formation, the resulting particles may be defective, for example the virion may not have packaged all segments of its genome, or may lack a key viral enzyme to replicate or attach to target cells. As a result, the virion is functionally incompetent as it is unable to infect another cell.

By contrast, a plaque forming unit (PFU) is a fully-formed virus that can actually trigger lytic infection in a new cell, namely infect and destroy it. This name comes from the plaque assay, where cell death is visualised as a circular area of lysis (a plaque) on a monolayer of cells, and serial dilutions are used infer the quantity of virus corresponding to a single lysis event.

Viruses widely vary in their particle/PFU ratio. For example, this ratio is 20-50 for Influenza A virus, but up to 10'000 for papilloma virus. This means that out of 10'000 papilloma virions, only 1 is actually able to generate productive viral infection. So, not all physical virus particles are infectious

I see the process of writing, or more generally of formulating and sharing ideas, as a process that can also be quantified with the particle/PFU ratio. Namely, out of all the things I try to say or write about, many of them maybe lack the substance, correct architecture or completeness to make a truly "functional" and "valuable" idea. These are the particles. I prefer this to the signal/noise ratio division, because these are not exactly noise. They are attempts, unfruitful attempts, but attempts nevertheless, and I think it is important to try anyway, hoping that one odd thought might actually engraft in someone's mind and create something worthwhile.

So, you can judge for yourself what pieces of writing are particles or true PFUs. I do not believe all of them are PFUs, but I am documenting the process of viral evolution that goes on in my mind, and can let you judge :)