Why is the AOF classification different between the 1 mL MXs521 and the 5 mL MX521?

The difference comes down to packaging, not biology or manufacturing. 1 mL MXs521 contains the same Biolaminin® 521 MX protein solution as the 5 mL MX521 — same biology, same performance. But AOF status applies to the complete product, including primary packaging, not just the protein solution or manufacturing process itself. The primary packaging used for MXs521 does not currently carry the same animal-origin-free documentation as the packaging used for MX521.