Branched DNA Signal Amplification Assay (bDNA) is a molecular biology technique used to detect and quantify specific nucleic acid sequences, such as DNA or RNA, in a sample. It is a sensitive and precise method that utilizes signal amplification to enhance the detection of target molecules.
In the bDNA assay, target molecules are initially captured by specific probes that have a high affinity for the desired sequence. These probes are designed to have a branched structure, consisting of multiple nucleic acid arms, each capable of binding to a different part of the target sequence. After hybridization between the target and capture probes, additional probes, called “pre-amplifier” and “amplifier” probes, are introduced.
The pre-amplifier probes contain multiple binding sites for the amplifier probes and the “label probes.” The amplifier probes, in turn, have numerous binding sites for the label probes. The label probes are conjugated with alkaline phosphatase or another enzyme, which generates a signal when a substrate is added.
As the bDNA assay proceeds, the signal is amplified through a series of hybridization and washing steps, resulting in the accumulation of labeled probes bound to the target molecules. The generated signal is then quantified using a suitable detection system, such as absorbance, fluorescence, or chemiluminescence, allowing for the precise measurement of the target nucleic acid concentration in the sample.
Overall, the Branched DNA Signal Amplification Assay is a powerful molecular biology technique that enables the sensitive and accurate detection and quantification of nucleic acid sequences. It finds application in various fields, including medical diagnostics, genetic research, and infectious disease monitoring.
