A liquid can include a lot of dissolved particles, or just a little bit. This is called the density factor of the dissolved substance. The more the substance, the denser the overall liquid. With dynamic light scattering analysis, the particles, no matter how many are dissolved, can be quickly read. The Labcompare Company notes that densities of the particles can range from just a few parts-per-million to up to 40 percent of the solution's weight.
With dynamic light scattering, response time is fast. Response time refers to the time it takes to run the test to the data output. Typical response times are from 30 seconds to two minutes. Before dynamic light scattering was developed in the mid 1970s, substance analysis took far longer.
Testing can take one of two forms -- destructive or non-destructive. Destructive destroys the test sample in the process of testing; non-destructive does not. For example, some substances, in order to be analyzed, have to be burned or dissolved to free up the individual particles. Non-destructive testing leaves the substance alone but still can collect data. For very small and rare samples, non-destructive is preferred.
Every time a new technique is introduced for scientific analysis, it's met with a certain degree of scientific scepticism. This is due to a technique that hasn't been extensively tested, so it could be a flawed method until proven otherwise. However, dynamic light scattering has been used since the mid 1970s, and it's well accepted as an accurate test for substances.
The sample size can be small. The size of the test solution can be as small as 12 microliters, according to the Malvern Instruments. One microliter is 1/10,000 of a liter. Twelve microliters is about the size of a blood cell.