AssayIndex
Annotator

counterion_mol

Counter-ion stoichiometry per basic residue, and the arithmetic people skip.

first seen 2025-Q10 records submitted43 annotations
Section 1

Contribution

Comments technically on records submitted by others. Annotations are signed and are not moderated for agreement.

Records submitted 0 n=0
Annotations 43 n=43
Median purity submitted suppressed n=0 n<3 — see individual records
Suppliers covered 0 n=0

This handle has submitted no records. Annotators comment on other people's submissions and are not required to submit.

Section 2

Annotations

Signed technical comments on records. The index does not moderate annotations for agreement with its own arithmetic, and several of these disagree with it. Where a handle has made the same point on several records, one instance is shown and the rest are reachable from the records themselves.

AX-2026-042572
Closure is a property of the index's arithmetic, not evidence about the material. What it establishes is that the four numbers on this record are mutually consistent.
AX-2026-041261
Counter-ion is measured on this record, which puts it in a minority. Without it the gravimetric mass balance cannot close and recovered peptide mass cannot be computed at all.
AX-2026-042132
3.69 % acetate against the number of basic residues in PT-141 (Bremelanotide) is the stoichiometric check. It agrees here, which means the salt is the salt and not an excess of reagent.
AX-2026-041218
6.95 % acetate against the number of basic residues in Thymulin is the stoichiometric check. It agrees here, which means the salt is the salt and not an excess of reagent.
AX-2026-042467
Stoichiometry per basic residue is arithmetic anybody can do from the sequence, and it converts a counter-ion percentage from a number into a check. Very few people do it.
AX-2026-043262
A basic peptide with four charged residues will carry roughly four equivalents of counter-ion at full protonation. Anything materially above that is excess reagent rather than salt form.
AX-2026-041855
4.03 % acetate against the number of basic residues in PT-141 (Bremelanotide) is the stoichiometric check. It agrees here, which means the salt is the salt and not an excess of reagent.
AX-2026-042547
7.09 % acetate against the number of basic residues in GHRP-2 is the stoichiometric check. It agrees here, which means the salt is the salt and not an excess of reagent.
AX-2026-043469
The stoichiometric prediction and the measured figure agree closely enough on this record that no excess reagent need be postulated. That is a quiet, useful result.
AX-2026-042287
Hydrochloride, acetate and trifluoroacetate differ in formula weight by more than a factor of two. The same molar loading produces very different percentages and comparing percentages across salt forms is meaningless.
AX-2025-020481
Check the stoichiometry: 13.41 % acetate is close to what the number of basic residues in KPV predicts, so this is the expected salt rather than an excess. The arithmetic is on the counter-ion method page.

Showing 12 distinct comments of 43 annotations by this handle.