1X Passive Lysis Buffer 2.0 for Biotium’s Firefly & Renilla Luciferase Single Tube Assay Kits (catalog no. 30081) is sold separately for use with the kits when more lysis buffer (e.g. >100 uL/well) is required. It also can be used with recombinant firefly or Renilla luciferase enzymes.