-DEAE cellulose columns are rarely used at pH greater than 8.5. Why?

DEAE cellulose columns are weak anion exchangers. This means that they contain a positively charged resin that binds to negatively charged proteins. Raising the pH above 8.5 will induce a negative charge on the resin.

Explanation:

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.