Distinguishing between bull Y- and X-bearing sperm populations is advantageous for techniques with sexed bull semen. The aim of this study was to produce a single-chain fragment variable (scFv) antibody against plasma membrane epitopes on bull Y-bearing sperm to distinguish between Y- and X- sperm. Variable heavy (VH) and variable light (VL) region genes generated from a hybridoma cell secreting a specific Y-bearing sperm monoclonal antibody (mAb-1F9) were cloned and expressed. The expected sizes of the DNA bands were ~350 bp for the VH gene and ~318 bp for the VL gene. The VH and VL genes were generated and used to construct an scFv gene (~650 bp) and express the corresponding soluble scFv antibody. Compared with the parent mAb-1F9, the scFv antibodies presented a high affinity for Y-bearing sperm and low cross-reactivity with X-bearing sperm. An immunofluorescence analysis confirmed that the scFv antibodies and mAb-1F9 recognize epitopes on the Y-bearing sperm surface. The fluorescence signal was strong on the plasma membrane of Y-bearing sperm but very weak for X-bearing sperm. This study helps the application and production of engineered scFv antibodies specific to Y-bearing sperm to distinguish between Y- and X-bearing sperm populations for techniques involving sexed bull semenTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV