https://www.theregister.co.uk/2018/07/06/dna_neural_networks/

Scientists have built neural networks from DNA molecules that can recognise handwritten numbers, a common task in deep learning, according to a paper published in Nature on Wednesday.

It’s pretty easy for traditional convolutional neural networks. Now, scientists are testing wackier models on the MNIST database of training images, like one network modeled on moth brains or made out of DNA. Researchers at the California Institute of Technology have strung together nucleotides to create molecular logic gates.