The Southern Blot technique detects A. DNA. B. RNA. C. proteins. D. recombinant DNA. E. specific genetic marker sequence on genes

The Southern Blot technique is a molecular biology method used to detect specific sequences of DNA within a complex mixture. Developed by Edward Southern in the 1970s, it involves the transfer of DNA fragments from a gel to a membrane, followed by hybridization with a labeled probe complementary to the target sequence.

1. Detection of DNA: The primary application of the Southern Blot is to identify specific DNA sequences among a vast background of other DNA fragments. This makes option A (DNA) the correct answer.

2. Other Options:

   • Option B (RNA): The detection of RNA sequences is done using a different technique called Northern Blot.
   • Option C (proteins): Proteins are typically analyzed using techniques like Western Blot.
   • Option D (recombinant DNA): While the Southern Blot can potentially be used to detect recombinant DNA if it contains known sequences, this is not its primary purpose.
   • Option E (specific genetic marker sequence on genes): Although it can be used to identify genetic markers, the essence of Southern Blot is the detection of DNA.

In conclusion, the Southern Blot technique primarily detects DNA sequences. Therefore, the correct answer is:

Final Answer

A. DNA.