pFLD and pFLDalpha are Pichia pastoris expression vectors designed for methylamine-induced expression and rapid protein purification and detection. The vectors feature:

 FLD promoter for inducible expression with methylamine (1)
 C-terminal V5 epitope and polyhistidine (6xHis) region for convenient detection with an Anti-V5 antibody and purification using nickel-chelating resin
 α-factor secretion signal for efficient transport of proteins to the medium (pFLDalpha only)