The assay value names the active marker, not the whole plant
A botanical extract is defined by its quantified active marker, not by the botanical name alone. Curcumin 95% means curcuminoids standardized to 95% by HPLC; green-tea extract 98% refers to tea polyphenols 98% with EGCG 50% by HPLC/UV. Always name the marker and the method together.
Match the method to the marker
Different markers need different methods. Polyphenols and curcuminoids are usually by HPLC or UV; beta-glucans in reishi and lion's mane are by Megazyme enzymatic assay (AOAC 995.16); cordycepin is by HPLC; nattokinase activity is by enzymatic assay expressed as FU/g (for example 20,000 FU/g). The method on the COA must match the one you specified.
Confirm the assay basis during RFQ
Some products offer several assay grades — for example chlorogenic acid 5% or 98%, or ginseng total ginsenosides 80% versus monomer Rg1 50%. State the exact marker, percentage and method in the RFQ so the supplier confirms the right SKU and COA, rather than a generic grade that fails your incoming release testing.
Read the COA against your specification, not in isolation
Check that the batch COA reports the marker, the result, the method, the unit (percent, mg/g, FU/g) and the reference standard. A trustworthy COA is tied to a real batch and shows the result against the specification band you requested. HerbalSourcing confirms the marker, method and unit per RFQ and pairs the batch COA with the shipped lot.