Carbohydrates

MAC uses a validated enzymatic assay to quantify lactose in human milk and related samples by specifically hydrolyzing lactose into glucose and galactose, followed by enzymatic conversion of glucose to generate a measurable signal. This method is highly specific and accurate, minimizing interference from other milk carbohydrates and components. It provides reliable lactose concentrations across a wide dynamic range, making it well suited for nutritional and clinical studies of human milk.

MAC uses high-performance liquid chromatography with fluorescence detection (HPLC-FL) following 2-aminobenzamide (2AB) labeling to quantify human milk oligosaccharides (HMOs). The reducing end of HMOs is tagged with the 2AB fluorescent label. The labeled HMOs are separated by HPLC, allowing sensitive and reproducible detection of individual oligosaccharide species. This approach enables accurate relative and absolute quantification of major HMOs across complex human milk samples as well as other matrices like blood, urine, amniotic fluid, tissue culture or bacterial supernatants.

The following HMOs - representing over 90% of the total HMO composition of human milk - are currently quantifiable with confidence (CV%<5%): 2′-fucosyllactose (2′-FL), 3-fucosyllactose (3-FL), 3′-sialyllactose (3′-SL), 6′-sialyllactose (6′-SL), difucosyllactose (DFLac), lacto-N-tetraose (LNT), lacto-N-neotetraose (LNnT), lacto-N-fucopentaose I (LNFP I), lacto-N-fucopentaose II (LNFP II), lacto-N-fucopentaose III (LNFP III), sialyl-LNT b (LST b), sialyl-LNT c (LST c), difucosyl-LNT (DFLNT, isomer mixture), disialyllacto-N-tetraose (DSLNT), lacto-N-hexaose (LNH), fucosyl-LNH (FLNH, isomer mixture), difucosyl-LNH (DFLNH, isomer mixture), fucosyl-disialyl-LNH (FDSLNH, isomer mixture), and disialyl-LNH (DSLNH).