What technique is described as systematically diluting a substance?

The technique that involves systematically diluting a substance is serial dilutions. This method is commonly used in microbiology to reduce the concentration of a sample in a stepwise manner. By diluting the sample through a series of defined dilution factors (for example, 1:10 or 1:100), it allows for the quantification of microorganisms or substances present in the original sample. Each dilution reduces the concentration, making it easier to analyze the microbes or substances when cultured or tested, ensuring that they can be counted or measured accurately.

Serial dilutions are essential for determining the number of viable cells in a sample and for preparing samples for further experiments when specific concentrations are needed. The systematic approach ensures consistent and replicable results, which is critical in experimental settings.

In contrast, while filtration is a method used for separating solids from liquids or removing microbes from solutions, and incubation refers to the maintaining of controlled conditions for growth after inoculation, concentration typically refers to the process of increasing the amount of a given substance within a solution, which is the opposite of dilution.