TABLE 1.

Summary of calibration and sample handling by instrument¹

	FiltMid	FTMid1	FTMid2	Near
Operator	Trained milk bank technician	Trained milk bank technician	Trained milk bank technician	Trained milk bank technician
Calibration set	Manufacturer calibration samples	Human milk samples (10) analyzed by USDA	Study calibration samples (10)	Study calibration samples (10)
Volume required for duplicate readings	6 mL	50 mL	60 mL	6 mL
Thawing	Overnight in refrigerator	Overnight in refrigerator	Overnight in refrigerator	Overnight in refrigerator
Warming	To 40°C in a bead warmer (heater model JBN5 US, Miris)	Temperatures at analysis 4°–8°C. Pilot study on effect of temperature showed no difference in results at starting temperatures of 4°C, 24°C, and 40°C (unpublished data).	To 20°C in water bath (Precision 183, Fisher Scientific)	To 40°C in bead warmer (heater model JBN5 US, Miris)
Mixing	Per manufacturer instructions	Sonicated at 75% amplitude 2 min with 6-mm probe submerged ∼75% into sample (VCX 130, Sonics and Materials)	Sonicated at 75% amplitude 3 min with 6-mm probe submerged ∼75% into sample (VCX 130, Sonics and Materials)	Sonicated at 50% amplitude for 15 s (ultrasonic processor model CV18, Miris); sample gently inverted 10 times before loading

¹FiltMid (Miris HMA), FTMid1 (MilkoScan), FTMid2, (LactoScope), and Near (SpectraStar). FiltMid, filtered midinfrared; FTMid, Fourier-transformed full-spectra midinfrared; Near, near infrared.