Ensuring the health of umbilical cord blood samples and their freedom from any microbial contamination is a serious focus of the quality control department. This examination is carried out in the **microbiology laboratory**, and if contamination of the sample with pathogenic microbial agents is proven, the sample is removed from the freezing process. The most significant cause of microbial contamination is contamination during blood collection from the umbilical cord in the delivery room, which, fortunately, has been significantly reduced through continuous training of blood collection specialists.