Which technique utilizes both immobilized probes and signal amplification for detecting nucleic acids?

The technique that utilizes both immobilized probes and signal amplification for detecting nucleic acids is Hybrid capture. In this method, nucleic acids are hybridized to specific probes that are immobilized on a solid substrate. The hybridization event forms a stable nucleic acid–probe complex. Once the target nucleic acids are captured, signal amplification is achieved through various mechanisms, which allows for the detection of even low-abundance targets.

Hybrid capture is particularly useful in various applications, such as detecting viral infections, genotyping, and identifying specific mutations. The combination of immobilized probes provides specificity while signal amplification enhances sensitivity, making this technique a powerful tool in molecular biology.

Other techniques listed do not fit this description. For example, Western blotting primarily detects proteins, whereas ELISA is a method for detecting antibodies or antigens in a sample, both of which do not involve the specific detection of nucleic acids with immobilized probes. Polymerase chain reaction (PCR) amplifies nucleic acids but does not typically involve the use of immobilized probes on a solid substrate for detection purposes, instead relying on the amplification of DNA to achieve detection.