Chromatography Forum

Why is the migration of AMP different to ATP in NaCl but not in water?

options:

1. In water both are negatively charged and bind to PEI but in NaCl the Na+ ions neutralise AMP more than ATP so AMP migrates more

2. In water both are negatively charged and bind to PEI but in NaCl the Cl- ions are more able to displace AMP than ATP with its larger negative charge

3. In water both are negatively charged and bind to PEI but in NaCl the pH rise makes ATP more charged so it migrates less

4. In water both are negatively charged and bind to PEI but in NaCl the Cl- ions are more able to displace ATP due to its lower negative charge than AMP

5. In water both are positively charged and bind to PEI but in NaCl the ATP is more charged so migrates less

This and your previous thread have the "look and feel" of homework or exam questions. What do *you* think is the answer (and why). If you're wrong, someone will point you in the right direction.

I think the answer is option 2 because ATP has a higher negative charge then AMP so Cl- will displace AMP further.

Very good!