Invitrogen CellBlox Plus Blocking Buffer is formulated to block nonspecific binding of NovaFluor labels with cells. These nonspecific interactions can result in higher background labeling. CellBlox Plus Blocking Buffer is a non-antibody blocking solution and should be used whenever a NovaFluor dye is used for labeling of any cell type. CellBlox Plus Blocking Buffer has enhanced blocking capabilities compared to our original CellBlox Blocking Buffer (Figure 1).

CellBlox Plus Blocking Buffer is also recommended for use with cyanine-based dyes or cyanine-based tandem dyes to block non-specific interactions with monocytes and macrophages to minimize background labeling (Figure 2).

Features of CellBlox Plus Blocking Buffer include:
• Compatible with all fluorophores and with LIVE/DEAD Fixable dead cell stains
• Can be used with any fluorophore-antibody conjugate as high-performance monocyte and macrophage blocking solution
• Compatible with other blocking reagents, such as Fc Block, blocking proteins, Brilliant Stain Buffer, and Super Bright Complete Staining Buffer
• Not required when labeling antibody-capture beads, such as UltraComp eBeads Plus Compensation Beads

Use of CellBlox Plus Blocking Buffer requires minimal change to most flow cytometry staining protocols. Simply add CellBlox Plus Blocking Buffer to an antibody cocktail mixture prior to labeling cells. Specifically, add 5 µL CellBlox Plus Blocking Buffer for every stained sample to be labeled with the antibody cocktail mixture, with 100 µL as a final staining volume.