Which type of gel is suitable for fragments smaller than 1,000 base pairs?

Polyacrylamide gel is particularly well-suited for the separation of nucleic acid fragments smaller than 1,000 base pairs due to its fine pore size and high resolution capabilities. This type of gel is commonly used for analyzing smaller DNA fragments, such as oligonucleotides and PCR products, because it can effectively resolve differences in size that are often subtle within this range.

The matrix of polyacrylamide allows for greater control over the density of the gel, which can be adjusted to improve resolution for smaller fragments. This is particularly advantageous for applications such as DNA sequencing or analyzing band sizes in electrophoresis, where the precision of size discrimination is crucial.

In contrast, agarose gel electrophoresis is generally preferred for larger fragments, as the larger pore size is more accommodating to DNA fragments typically larger than 100 base pairs. While agarose can accommodate smaller fragments, it does not provide the same level of resolution for fragments smaller than 1,000 base pairs compared to polyacrylamide.

Silica is not a gel matrix used in electrophoresis for separating DNA fragments; rather, it is often utilized in methods for extracting nucleic acids. Starch gel is used less frequently in modern molecular biology applications and