What is the typical size range for DNA strands analyzed using the Sanger method?

The Sanger method, also known as chain termination sequencing, is primarily used for determining the nucleotide sequences of DNA. The typical size range for DNA strands analyzed using this technique is between 100 and 1000 base pairs (bp). This range is important because the method relies on the ability to accurately generate and read the lengths of DNA fragments produced during the sequencing process.

In the Sanger method, DNA is amplified and then processed to incorporate dideoxynucleotides that terminate DNA strand elongation at specific bases, allowing for the identification of the sequence. The resultant fragments must be of a manageable size for the gel electrophoresis method used to separate them, with 100 to 1000 bp providing a good balance between resolution and sequence information. This allows the method to be effective for sequencing shorter regions of DNA while still maintaining accuracy.

Larger sizes, beyond this range, can often lead to complications in sequencing fidelity and data interpretation. Thus, the size range of 100-1000 bp is optimal and makes up the standard for many applications of the Sanger sequencing technique.