Researchers discovered that the logic of a Sudoku mathematical puzzle can be used to understand genome-sequencing, and thus, the growing field of genetics. The researchers called their discovery “DNA Sudoku” in which a 2,000-year-old Chinese mathematical theorem was combined with several concepts from cryptology. In the past, only a single DNA sequence could be seen at one time; then a method to determine several hundred at a time was developed.

But the DNA Sudoku outdoes them all, allowing tens of thousands of DNA samples to be combined, along with their sequences determined (with the four bases in DNA, represented by the letters A for adenine, G for guanine, C for cytosine, and T for thymine) all at once. Not only does it speed up sequencing, it reduces the amount of money spent on the task, from upwards of $10 million to only tens of thousands of dollars with the DNA Sudoku method. Not only does it save money, it also speeds up sequencing when exploring how certain DNA sequences are associated with genetic diseases such as TaySachs. This way, individuals who carry the disease-causing mutations can easily be identified.

The DNA Sudoku researchers’ goal was to speed up the sequencing of many samples (called multiplexing). To do this, each sample is tagged with a “barcode,” a short string of DNA letters identifying the sample. From there, the samples were sequenced, with the barcode tags telling the researchers which sequence belonged to what sample. But making a single barcode for each sample was time consuming and costly, especially since there are thousands of samples to examine. The researchers then decided to mix the samples in certain patterns, making “pools” of samples with one barcode, all based on the Chinese remainder theorem. They named the entire method DNA Sudoku because of its resemblance to the logic and combinatorial number-placement rules of the Sudoku game we all know and love to play.