Aims:The aim was to define the source of contamination of cryoprecipitate intercepted during visual inspection before transfusion.Materials and Methods: A clot was observed in one unit of cryoprecipitate before blood transfusion at the Dongyang People's Hospital. Bacterial cultures were performed using the BacT/ALERT system (BacT/ALERT 3D, bioMerieux, Durham, NC). The isolated bacteria were identified through conventional biochemical identification, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and molecular analysis based on 16sr RNA. Samples from all individuals who came into direct contact with the cryoprecipitate were cultured, and the positive samples were then referred for bacterial identification. Results: A leak was found at the edge of a blood bag containing the cryoprecipi-