2,695
edits
Lidstrom:Buffers: Difference between revisions
From OpenWetWare
Jump to navigationJump to search
→Notes specific to buffers
| Line 109: | Line 109: | ||
* Phosphates, for example, form insoluble salts with bivalent metals and precipitate. Phosphate buffered salt solution (PBS) is never autoclaved with Ca2+ or Mg2+ for this reason. Good buffers, such as PIPES, TES, HEPES and CAPS have very low metal-binding constants and are therefore particularly suited to investigate metal-dependent enzymes (Good & Izawa 1972, Blanchard 1984). [http://www.applichem.com/fileadmin/Broschueren/BioBuffer.pdf Applichem] | * Phosphates, for example, form insoluble salts with bivalent metals and precipitate. Phosphate buffered salt solution (PBS) is never autoclaved with Ca2+ or Mg2+ for this reason. Good buffers, such as PIPES, TES, HEPES and CAPS have very low metal-binding constants and are therefore particularly suited to investigate metal-dependent enzymes (Good & Izawa 1972, Blanchard 1984). [http://www.applichem.com/fileadmin/Broschueren/BioBuffer.pdf Applichem] | ||
*Phosphates and pyrophosphate are both substrates and inhibitors of different enzyme reactions (inhibition of carboxypeptidase, urease, various kinases, various dehydrogenases). [http://www.applichem.com/fileadmin/Broschueren/BioBuffer.pdf Applichem] | *Phosphates and pyrophosphate are both substrates and inhibitors of different enzyme reactions (inhibition of carboxypeptidase, urease, various kinases, various dehydrogenases). [http://www.applichem.com/fileadmin/Broschueren/BioBuffer.pdf Applichem] | ||
* Phosphates inhibit many enzymatic reactions and procedures that are the foundation of molecular cloning, including cleavage of DNA by many restriction enzymes, ligation of DNA, and bacterial transformation. ([http://www.unl.edu/cahoonlab/phosphate%20buffer.pdf source]) | |||
* Because phosphates precipitate in ethanol, it is not possible to precipitate DNA and RNA from buffers that contain significant quantities of phosphate ions. ([http://www.unl.edu/cahoonlab/phosphate%20buffer.pdf source]) | |||
* Phosphates sequester divalent cations such as Ca2+ and Mg2+. ([http://www.unl.edu/cahoonlab/phosphate%20buffer.pdf source]) | |||
=== Tris buffer === | === Tris buffer === | ||
