: A gene (like ampicillin resistance) that allows scientists to identify bacteria that have successfully taken up the vector.
| Vector Type | Insert Size Capacity | Delivery Method | | :--- | :--- | :--- | | | Small (< 15 kb) | Chemical Transformation / Heat Shock | | Cosmid | Large (35–45 kb) | Phage Infection (Lambda) | | BAC (Bacterial Artificial Chromosome) | Very Large (100–300 kb) | Electroporation | cosmid net
A cosmid is essentially a plasmid that has been engineered to contain a specific sequence derived from the λ (lambda) bacteriophage, known as the (cohesive end site). : A gene (like ampicillin resistance) that allows
This is the most critical feature. Sourced from the lambda phage, it provides a sequence of roughly 200 base pairs that contains a 12-base single-stranded cohesive end. This sequence is recognized by the lambda packaging enzymes, allowing the DNA to be packed into viral heads. Sourced from the lambda phage, it provides a
In molecular biology, a is a type of hybrid cloning vector that combines the useful features of both bacterial plasmids and the lambda ( ) bacteriophage. The name is a portmanteau of " site" and "plas Composition and Structure
, which then "inject" the DNA into the host bacteria with high efficiency. Key Applications Cosmid - an overview | ScienceDirect Topics
First described by Collins and Hohn in 1978, a typical cosmid vector is small (around 5 kb) but contains specific elements from both plasmids and viruses: Cosmid Vector - an overview | ScienceDirect Topics