Isolati

Isolati, in scientific contexts, are samples derived from a larger population that have been separated for examination; in English, the term is isolates. In microbiology, an isolate is a pure culture derived from a single organism, representing a clonal lineage distinct from other organisms in the original specimen. Isolates are obtained by sampling a mixed community, culturing on selective or differential media, and performing successive streaking to obtain a single colony. Once established, an isolate can be preserved by cryopreservation or lyophilization and stored in culture collections under unique accession numbers (for example, ATCC, DSMZ).

Characterization of isolates includes phenotypic assays (morphology, metabolism, antigenic properties) and molecular typing (PCR, sequencing, whole-genome sequencing) to determine species, genotype, and relatedness to other isolates. In clinical practice, patient-derived isolates guide antimicrobial susceptibility testing and treatment decisions; in epidemiology, comparing isolates from different patients or sources helps track transmission and origin of outbreaks. In environmental microbiology, isolates reveal diversity, ecological roles, and potential biotechnological applications. The concept also extends to plant, animal, and microbial systems where isolates support taxonomy and evolutionary studies.

Storage, handling, and transport of isolates require strict aseptic technique to prevent contamination and preserve viability. Challenges include contamination, genetic drift during subculturing, and biases introduced by growth conditions or selective media. Non-culturable organisms may necessitate alternative approaches such as metagenomics to study their genomes as isolates or near-isolates.

See also: culture collection, strain, clone, antimicrobial susceptibility testing, genome sequencing, typing method.