Name two buffers commonly used in molecular biology workflows and their general purpose.

Name two buffers commonly used in molecular biology workflows and their general purpose.

• A. Tris buffer for PCR and phosphate buffer for gel
• B. TAE or TBE buffers for gel electrophoresis; PCR buffers maintain pH and provide Mg2+
• C. Acetate buffers for sequencing
• D. Bicarbonate buffers for chromatography

Answer: (B)

Buffers provide a stable chemical environment by keeping pH and ionic conditions consistent, which is essential for both enzymes to work properly and for techniques that rely on electrical current. For gel electrophoresis, the running buffer carries the electric current through the gel and keeps the pH in a range that preserves DNA’s charge so it migrates predictably toward the positive electrode. The two most common options are TAE and TBE buffers. They’re chosen because they offer reliable buffering, appropriate conductivity, and compatibility with DNA separation, helping you resolve fragments by size clearly. For PCR, the reaction buffer sets the right pH and supplies magnesium ions, which are crucial cofactors for the DNA polymerase. Without Mg2+, the enzyme won’t function efficiently, and amplification can be poor or fail altogether. So a PCR buffer that maintains stable pH and provides Mg2+ supports consistent, efficient DNA synthesis. Other buffers mentioned aren’t standard in these workflows because their typical roles or properties don’t align with these needs—sequencing or chromatography use different buffer systems and conditions.

Buffers provide a stable chemical environment by keeping pH and ionic conditions consistent, which is essential for both enzymes to work properly and for techniques that rely on electrical current.

For gel electrophoresis, the running buffer carries the electric current through the gel and keeps the pH in a range that preserves DNA’s charge so it migrates predictably toward the positive electrode. The two most common options are TAE and TBE buffers. They’re chosen because they offer reliable buffering, appropriate conductivity, and compatibility with DNA separation, helping you resolve fragments by size clearly.

For PCR, the reaction buffer sets the right pH and supplies magnesium ions, which are crucial cofactors for the DNA polymerase. Without Mg2+, the enzyme won’t function efficiently, and amplification can be poor or fail altogether. So a PCR buffer that maintains stable pH and provides Mg2+ supports consistent, efficient DNA synthesis.

Other buffers mentioned aren’t standard in these workflows because their typical roles or properties don’t align with these needs—sequencing or chromatography use different buffer systems and conditions.