摘要 |
The present invention provides a probe for use in detecting a target analyte in a sample, wherein the probe provides or is capable of providing nucleic acid components sufficient to initiate a rolling circle amplification (RCA) reaction, said probe being a nucleic acid construct comprising: (i) one or more target binding domains capable of binding to said target analyte or an intermediate molecule bound, directly or indirectly, to the target analyte; (ii) one or more domains together comprising or capable of providing a circular or circularisable RCA template; (iii) a domain comprising or capable of providing a primer for said RCA reaction that hybridizes to a region of said circular or circularisable RCA template; and, when the probe comprises or is capable of providing a circularisable RCA template, (iv) one or more domains comprising or capable of providing a ligation template that templates the ligation of the circularisable RCA template, wherein at least part of the probe must be cleaved and/or unfolded to release said primer to enable said rolling circle amplification reaction. Also provided are methods for detecting analytes in a sample using the probe of the invention. In certain preferred embodiments of the probe cleavage of the probe into multiple parts each held in proximity by a target binding domain in each part of the probe generates a circularisable RCA template, which is circularised in a ligation reaction templated by a ligaton template domain of the probe. |