# Farrell's medium > selective bacteriological medium for Brucella species **Wikidata**: [Q25326621](https://www.wikidata.org/wiki/Q25326621) **Wikipedia**: [English](https://en.wikipedia.org/wiki/Farrell's_medium) **Source**: https://4ort.xyz/entity/farrell-s-medium ## Summary Farrell's medium is a selective bacteriological growth medium specifically designed to cultivate *Brucella* species. It functions as a specialized nutrient environment that supports the growth of these bacteria while inhibiting the propagation of other microorganisms. ## Key Facts - **Classification**: Instance of a growth medium. - **Primary Function**: Serves as a selective bacteriological medium. - **Target Organism**: Specifically formulated for *Brucella* species. - **Google Knowledge Graph ID**: /g/11bxfv3fff. - **Wikipedia Presence**: Maintains a single sitelink in the English language. - **Wikidata Description**: Defined as "selective bacteriological medium for Brucella species." ## FAQs ### What is Farrell's medium used for? Farrell's medium is used in microbiology to selectively grow *Brucella* species, a genus of bacteria, while suppressing the growth of other organisms. ### What category of laboratory tool does Farrell's medium belong to? It belongs to the category of growth media, which are liquid or gel substances used to cultivate microorganisms or cells in controlled environments. ### Is Farrell's medium a solid or liquid? As a growth medium, it can be formulated as either a liquid (broth) or a gel (usually solidified with agar), though its specific state depends on the particular preparation protocol used for *Brucella* cultivation. ## Why It Matters Farrell's medium matters because it addresses the specific challenge of isolating *Brucella* species, which are fastidious organisms that can be difficult to grow in standard culture conditions. By providing a selective environment, it enables researchers and medical professionals to detect and study these bacteria without interference from competing flora. This capability is essential for diagnosing Brucellosis and for conducting research related to this specific bacterial genus. As part of the broader ecosystem of growth media, it represents the customization necessary to target specific pathogens, mirroring the utility of other selective media like Mueller-Hinton agar in antibiotic susceptibility testing. ## Notable For - **Specific Selectivity**: Unlike general-purpose media (e.g., Trypticase soy agar), it is chemically or biologically tailored to favor *Brucella* species exclusively. - **Targeted Application**: It is a specialized tool within the "growth medium" class, distinct from chemically defined media or serum-free media used for cell lines. - **Bacterial Isolation**: Notable for its role in the isolation phase of microbiological study, distinguishing it from enrichment media used to boost growth rather than select it. ## Body ### Definition and Target Organism Farrell's medium is a specialized formulation classified under the broader category of growth media. It is explicitly defined as a "selective bacteriological medium for *Brucella* species." Its primary purpose is to create an environment that allows these specific bacteria to thrive while inhibiting the growth of other microorganisms, a standard requirement for the isolation of specific pathogens from complex samples. ### Classification and Hierarchy The medium is an instance of a "growth medium" (also known as a culture medium). Growth media are fundamental tools in biology and medicine, defined as liquid or gel substances designed to support the growth of microorganisms or cells. - **Contextual Class**: It shares its classification with other media types such as chemically defined media, selective media, and serum-free media. - **Function**: Like other selective media (e.g., Mueller-Hinton agar), it likely contains specific inhibitors or nutrients that favor the target organism. ### Structural and Digital Identifiers Farrell's medium is indexed within major knowledge systems, reflecting its recognized status in the scientific community. - **Google Knowledge Graph ID**: /g/11bxfv3fff - **Wikipedia**: It has a dedicated entry titled "Farrell's medium" in the English language. - **Wikidata**: The entity has a sitelink count of 1. ### Broader Context of Growth Media As a member of the growth medium class, Farrell's medium operates within a framework established for cultivating life in vitro. - **Components**: While the specific recipe for Farrell's medium is not detailed in the provided source, growth media generally consist of nutrients, salts, carbohydrates, and moisture. - **Forms**: It exists within the paradigm of liquid or gel states, utilizing structural agents like agar if solid support is required for colony formation. - **Applications**: It is utilized in the same scope as other media for isolation, cultivation, and experimentation in microbiology and medical diagnostics. ### Relationship to General Growth Media Concepts The entity "Farrell's medium" inherits the properties and significance of its parent class, "growth medium." This relationship connects it to the foundational concepts of laboratory cultivation: - **Customizability**: It exemplifies the ability to formulate media for specific tasks, such as distinguishing or selecting bacterial species. - **Diagnostic Utility**: It serves the medical and research goal of isolating pathogens, a core function of growth media since early developments like the Ogawa medium in 1949. - **Standardization**: As a recognized medium, it contributes to the reproducibility of scientific experiments involving *Brucella*.