pEco Vector expresses the ecotropic envelope protein under the control of the CMV immediate-early promoter (1). The ecotropic envelope protein can serve as a surrogate viral envelope protein (2). It interacts on the host cell surface with the ecotropic receptor protein, murine cationic amino acid transporter-1 (MCAT-1) which facilitates rat or mouse host cell infection. pEco includes IVS, a synthetic intron known to enhance the stability of the mRNA (3), the pUC origin of replication, and the bacterial ampicillin resistance (Ampr) gene for propagation and antibiotic selection in bacteria.