Final answer:
STE buffer is used in molecular biology to preserve and protect DNA samples during handling and storage.
Step-by-step explanation:
STE (sterile TE buffer) is commonly used in molecular biology, particularly when working with DNA. STE buffer helps to maintain the stability and integrity of DNA samples by providing a stable pH environment and protecting the DNA from degradation. It is a mixture that typically contains Tris, which acts as a buffering agent to maintain a stable pH, EDTA, which chelates divalent cations like Mg2+ that are necessary for enzyme activities that could degrade DNA, and usually some NaCl to provide an ionic strength similar to that of the cell, which helps in processes like nucleic acid precipitation.