Abstract: A method for mapping the number and location of restriction enzymes sites for a given restriction enzyme in a target nucleic acid comprises the steps of (1) translocating a target nucleic acid having detectable elements characteristic of the presence of the restriction enzyme sites therein through an analysing device comprising a nanopore and a detection window and (2) causing the detectable elements to be detected as they pass though the detection window. Typically the detectable elements are formed by attaching to the restriction enzyme sites a restriction enzyme to which one or more marker moieties have been added. The data or signal obtained from the detection is suitably in the form of a distribution profile of the detectable elements, and therefore the restriction enzyme sites along the length of the target nucleic acid and can be used to create a reference set of like distribution profiles against which new distributions can be compared.

Abstract: Apparatus for building a stochastic model of a spatially related data sequence, the data sequence comprising symbols selected from a finite symbol set, the apparatus comprising: an input for receiving said data sequence, a tree builder for expressing said symbols as a series of counters within nodes, each node having a counter for each symbol, each node having a position within said tree, said position expressing a symbol sequence and each counter indicating a number of its corresponding symbol which follows a symbol sequence of its respective node, and a tree reducer for reducing said tree to an irreducible set of conditional probabilities of relationships between symbols in said input data sequence. The tree may then be used to carry out a comparison with a new data sequence to determine a statistical distance between the old and the new data sequence.

Abstract: Apparatus for building a stochastic model of a time sequential data sequence, the data sequence comprising symbols selected from a finite symbol set, the apparatus comprising: an input for receiving said data sequence, a tree builder for expressing said symbols as a series of counters within nodes, each node having a counter for each symbol, each node having a position within said tree, said position expressing a symbol sequence and each counter indicating a number of its corresponding symbol which follows a symbol sequence of its respective node, and a tree reducer for reducing said tree to an irreducible set of conditional probabilities of relationships between symbols in said input data sequence. The tree may then be used to carry out a comparison with a new data sequence to determine a statistical distance between the old and the new data sequence.