| An in vitro biological memory protocol was developed and implemented with a microarray as a recall protocol as a novel storage medium The in vitro biological memory protocol is a DNA computer and its procedure captures, stores, and retrieves information from unknown inputs. The in vitro biological memory protocol consists of two key steps, a learning protocol and an associative recall protocol. The learning protocol is designed to store information from an input into learned products. The stored information through the learning protocol is recalled by DNA-DNA hybridization using a microarray detection system. Theoretically, the in vitro biological memory protocol can store information from inputs without any prior information and can differentiate them by pattern separation using the microarray detection platform. Experimental results showed that the in vitro biological memory protocol has the capability to store and recall information, demonstrating its feasibility as designed to discriminate and classify the unknown sample identities, using Escherichia coli K12 and Bacillus subtilis as model input organisms. Also key indices of the sensitivity of the microarray detection system, i.e., the limit of detection and quantification, were evaluated to test the usability of microarray as a recall protocol. The results indicated the excellent capability of microarray as an effective detection platform for the in vitro biological memory protocol. However, further improvements are required to fully realize the potential of the in vitro biological memory protocol. The learning protocol should be further optimized and generalized to increase the learning capacity. Also the discrimination power of the recall protocol by microarray should be further improved. With further improvements and optimizations, it is expected that not only the excellent promise of the in vitro biological memory protocol could be realized as the pattern classifier, but also its applicability could be expanded to other various applications, such as an alternative labeling method for Southern, northern blotting or microarray experiments, an environmental monitoring method, a screening tool for the prognosis of human diseases, such as cancer and bacterial or viral infections, or a massive storage medium for non-biological information. |
