Table 5.

Recommendations for collecting and handling of HM samples.

Collection of samples
Standardize the time of sampling of HM to avoid diurnal variations
Agree on breasts for HM collection
Request mothers to completely empty the breast, ~2 h prior to collection of milk by feeding the infant or manual pumping to minimize the impact on nutrient concentration of interest by residual milk from previous feeding session
Realize single full HM sampling to ensure inclusion of fore-, mid-, and hind milk
Record the volume of milk
Standardize the collection of milk for all study subjects by either electrical pumping or hand pumping to minimize variation due to extraction method
Handling of samples
Store milk in smaller aliquots (e.g., 250 μL/aliquot) to avoid freeze-thaw cycles if multiple analyses are anticipated
Store aliquots of milk in tubes at −80°C as quickly as possible and at temperatures as low as possible in field collections until transfer to central laboratory for longer term storage
Analyses
Choose appropriate analytical method to characterize and quantify nutrients in HM, with respect to their selectivity, accuracy and precision