Cation-exchange chromatography is used when the molecule of interest is positively charged on the neutral pH. The stationary phase is than negatively charged and positively charged molecules are loaded to be attracted to it. So, positively charged peptides will elute the last.
The most likely answer here is 1 and 4.
Using a molecular<span>, scientists are able to estimate the amount of time that two species have been evolving independently.</span>lecular
<span>When the surface layer was dug up, the permafrost was exposed. When the weather warmed, this exposed permafrost would have melted and become soggy, causing the ground underneath the tracks to shift.</span>
