Biobanks are valuable service units that ensure the usage of high-quality biological samples. They contribute to translational research, and their support may improve future therapeutic approaches. They store biological samples that can be used to examine circulation biomarkers, immune cells, and immunohistochemistry aspects of illnesses and further in-depth examinations using NGS techniques. The IRCCS Synlab SDN Biobank has about 70,000 well-preserved cryopreserved human samples from various diseases, primarily oncological but also neurological and cardiovascular. These biospecimens were taken from 25,000 participants underwent imaging with a contrast agent. The goal is to propose quality control assays that meet the requirements of the international standard ISO 9001:2015 and ISO 20387:2020 accreditation. PBMCs viability was determined, and immune subset cells were analyzed by flow cytometry. Furthermore, the expression of ubiquitous miRNAs was used to assess plasma sample integrity. The quality controls demonstrated that the biological samples were correctly cryopreserved; the preservation of human biological samples did not affect the quality of the biological samples tested. Indeed, the cryopreserved PBMCs had a vitality of more than 80%, and the lymphocyte subsets could be selected for future immune cell investigations. Furthermore, miRNA expression was highest in thawed plasma samples compared to the positive and negative controls. We evaluated the quality of our randomly selected biobank-thawed human samples. Both PBMCs and plasma samples fulfill the high-quality standards needed for biomedical research, assuring their long-term preservation. However, further research is needed in the biobanking field to establish globally accepted procedures to confirm the quality of biological samples.