The Cd41 antibody binds thrombocytes and thrombocyte precursors in zebrafish kidney marrow and permits HSC enrichment. (A) The Cd41 antibody binds cd41:EGFP^High-positive cells (including thrombocytes) preferentially in kidney marrow. (B) Colony-forming assays suggest that Cd41 antibody-positive cells in kidney marrow include thrombocyte precursors. (C) Transplantation of sorted cd41:EGFP^Low kidney marrow cells reveals that the Cd41 antibody-positive cell fraction does not engraft, but that the Cd41 antibody-negative cell fraction does. (D) Representative flow cytometry plot from the kidney marrow of a transplant recipient at 3 months posttransplant. Multilineage engraftment is apparent based on the location of ubi:mCherry-positive cells (black) relative to live cells (blue) by light scatter characteristics.