PBT-I

Phosphate-buffered saline (PBS), prepared without added CaCl₂ or MgCl₂

Bovine serum albumin (BSA; Sigma-Aldrich)

Triton X-100

Prepare PBS with 0.2% BSA and 0.5% Triton X-100. Make fresh before use. Note that PBT-I for immunohistochemistry is different from PBT used in whole-mount in situ hybridization (PBT-H).