For solid or cereal samples what milling specification should they meet?

For most kits designed for starch and dietary fiber analysis, we suggest using a centrifugal grinding mill fitted with a 12-tooth rotor and a 0.5 mm sieve to mill cereal, plant, or food products. (For example, the Frisch Pulverisette 14 with a 0.5 mm screen, or a comparable device.)

For the K-YBGL assay kit, a sieve size of 1.0 mm is sufficient.