What is the main function of laboratory reagents?

Laboratory reagents play a crucial role in the analysis and processing of samples within a lab setting. The primary function of these substances is to provide the necessary materials that facilitate various chemical reactions and analyses. Reagents can include a wide range of chemicals, enzymes, or biological materials specifically designed to interact with the substances being tested. For instance, in a biochemical assay, reagents may help catalyze a reaction that produces a measurable change, which can then be quantified for diagnostic or research purposes.

The other options, while related to laboratory practices, do not capture the core purpose of reagents. Some may serve specific roles, like controls or pH measurements, but they do not encompass the broader functionality of reagents in sample analysis and chemical reactions, making the choice of providing materials for sample analysis and reactions the correct interpretation of their main function.