Method for constructing molecular sum gates using padlock probes for quantitating nucleic acid targets sums

A system for constructing molecular SUM gates using padlock probes for quantitating the sum of concentrations of a large number of different nucleic acid targets in a single reaction, the method comprising, the system comprising:

• characterized in that;
• a plurality of molecular SUM gates (122) that are generated by introducing a plurality of padlock probes that are designed for binding to each target in a set of nucleic acid targets (S), wherein each of the plurality of padlock probes comprises a universal region specific to a target nucleic acid and a variable region that enables detection of circularized probes;
• a testing device (124) that is configured to perform an assay for quantitating the sum of concentrations of the set of nucleic acid targets species (S) in a sample by:
• obtaining at least one circularized padlock probe from the plurality of padlock probes using a specific interaction of the at least one padlock probe with a target nucleic acid associated with the at least one padlock probe, and
• quantitating the sum of concentrations of the set of nucleic acid targets species (S) by means of quantification of the at least one circularized probe.