Abstract: The aim of this study was to develop a rapid and simple method for the determination of lactoferrin from fresh bovine milk, transgenic bovine milk and human milk. After removing fat by centrifugation and precipitating caseins by adjusting pH, the lactoferrin contents were separated by SDS-PAGE (100 V, 12 g/mL gel, comb:1.0 × 10 teeth, 5μL injection, staining for 3 h and destaining for 2 h); and then the target fractions in the gel were examined by thin layer chromatography scanner (transmission, zigzag scan, dual wavelength, swing width: 8 mm, delta Y: 0.1 mm). The results showed that good separation was achieved for lactoferrin (LF), α-lactalbumin (α-La) and β-lactoglobulin (β-Lg) from three different sources. The recoveries for LFI (LF standard obtained from fresh bovine milk) in fresh bovine milk and LFII (LF standard obtained from transgenic bovine milk) in transgenic bovine milk across three spike levels were 104.53% and 108.37%, respectively. The intra-plate assay precision RSDs for LFI and LFII were 3.1003% and 1.8151%, respectively. The calibration curves of LFI and LFII displayed a good linearity within the range of 100 to 2000μg/mL, with a correlation coefficient of respectively 0.9988 and 0.9990.

Key words: bovine lactoferrin, recombinant human lactoferrin, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), thin layer chromatography scanning