Fig 1. 1D-PAGE of sheep acid whey before and after ProteoMiner treatment.

Sheep acid whey was subjected to ammonium sulfate precipitation, desalting by 2 kDa cut-off dialysis and concentration to 60 mg.mL⁻¹ prior to treatment with a ProteoMiner kit according to the manufacturer’s instructions. The ProteoMiner enriched protein fraction was desalted using a 2D Clean Up Kit and one quarter of the material was separated by 1D-PAGE using a 12 well Novex BOLT 4–12% bis-Tris electrophoresis gel. Novex Sharp Pre-Stained Protein Standards (Life Technologies, Auckland, NZ) were run in one lane for calibration. The gel was stained with Simply Blue SafeStain (Invitrogen, Auckland, NZ). After staining, the Proteominer enriched sample whole gel lane was excised, cut into six segments as indicated and subjected to an in-gel digest/ LCMS/MS workflow. Lf, lactoferrin; Sa, serum albumin; Cn, casein; β-Lg, beta-lactoglobulin; α-La, alpha-lactalbumin; and Lz, lysozyme.