Which vector has >2000 kb capacity?
Insert capacity scales with vector complexity. Plasmids up to 10 kb, cosmids about 45 kb, fosmids and P1 about 70-100 kb, BAC and PAC up to 300 kb, YAC up to 1000-2000 kb. Mammalian artificial chromosomes and human artificial chromosomes constructed with mammalian centromeres and alphoid DNA can maintain inserts exceeding 2000 kb, sometimes several megabases, as independent chromosomes in host cells. This ultra-large capacity enables transfer of entire genomic loci with intact long-range regulatory elements, modeling aneuploidy and providing platforms for large transgene delivery where bacterial and yeast systems are insufficient.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.