High Throughput Biodosimetry for Radiation Countermeasure with a “Smart” Shipping Incubator
Mass nuclear catastrophe is a serious concern for society at large when considering the rising threat of terrorism and the risks associated with harnessing nuclear energy. In the case of a mass nuclear/radiological event that requires thousands or even millions of individuals to be assessed for radiation exposure, a rapid biodosimetry triage tool is crucial. The Cytokinesis Blocked Micronucleus Assay (CBMN) is a promising cytogenetic biodosimetry assay for triage; however, it requires shipping samples to a central laboratory (1-3 days), followed by a lengthy cell culture process (72 hrs), and then assay analysis (1-2 days), totaling to over a week, too long for effective patient care intervention. In this project, we test a “smart” shipping incubator that could reduce the CBMN assay time by half by allowing cell culture to start right after samples are collected and progress during shipment. The “smart” shipping incubator is equipped with a centrifuge that adds Cytochalasin B (Cyto-B), a cytokinesis blocker, during shipment to reduce the risk of jeopardizing the accuracy of the assay due to shipping delays. A Jurkat cell line was used as a model system for developing the CBMN assay and testing the “smart” incubator. The cells were successfully purified by Ficoll-Paque density gradient centrifugation after being revived from liquid nitrogen. DAPI staining was found to be more effective in binucleated (BN) and micronuclei (MN) labeling than Giemsa staining. An optimal Cyto-B blocking time of 48 hours was identified. Thymidine synchronization also demonstrated to obtain high yield of BN cells. The CBMN assay was tested on samples cultured in a traditional CO2 incubator and in the shipping incubator. The former showed a strong correlation between radiation dose (Gy) and the ratio of MN per 100 BN cells, while no such correlation could be obtained in the latter because the samples were deficient in BN cells and showed evidence of cell death and clumping. On the contrary, irradiated blood samples cultured in the conventional CO2 incubator and in the “smart” shipping incubator had significantly similar linear correlations between dose and MN/BM. Therefore, we conclude that the “smart” shipping incubator may not be ideal for conducting the CBMN assay on the Jurkat model but is capable of culturing blood samples just as effectively as a CO2 incubator. Future improvements include automating the MN counting process, redesigning the Cyto B release valves to handle more mechanical stress, and testing the system through commercial shipping companies.