unmodified

Unmodified is an adjective describing something that has not been altered, changed, or enhanced from its original state. The term is used across disciplines to indicate a baseline or reference condition and is often contrasted with modified, augmented, or processed forms. In general usage, it can apply to physical objects, substances, data, or biological molecules.

In science, unmodified substances are those that have not undergone chemical modification or functionalization. They may serve as controls in experiments. For example, unmodified nucleotides refer to the standard A, T/U, C, and G bases without any post-synthetic alterations. In materials science, unmodified polymers or surfaces retain their native chemistry absent grafting or coating.

In biology and biochemistry, the term commonly describes macromolecules that lack post-translational modifications or other chemical alterations. A protein produced in its unmodified form lacks PTMs such as phosphorylation or glycosylation. Researchers sometimes compare unmodified proteins to their modified counterparts to study the effects of modifications on stability, activity, or interactions.

In computing and information technology, unmodified data or files are those that have not been edited, compressed, encrypted, or otherwise transformed from their original form. Ensuring data remains unmodified is important for fidelity and reproducibility, and checksums or digital signatures are often used to verify integrity.

In linguistics, an unmodified word can refer to its base or lemma form, i.e., the canonical dictionary form before inflection or derivation. Conversely, inflected or derived forms are modified.