Amino acids are vital for fetal growth, and must be supplied by the mother via the placenta. Previously we have shown that the facilitated amino acid transporters TAT1 (slc16a10), LAT3 (slc43a1) and LAT4(slc43a2) mediate efflux of specific amino acids from the placenta into the fetal circulation. TAT1 and LAT3 mRNA levels in human placentas are related to measures of fetal growth whereas LAT4 mRNA levels are affected by maternal nutritional status. It is now important to establish how these transporters are regulated. This study aimed to establish whether the human choriocarcinoma, BeWo, cell line is a suitable model for investigating the regulation of facilitated amino acid transporters. BeWo cells were cultured in 35 mm diameter 6 well plates at 37C (5% CO2) in DMEM/Ham F-12K nutrient mix supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin. At 70-80% confluence cells were harvested for RNA and protein extraction. Total RNA was extracted (Ambion mirVanaTM miRNA isolation kit) and reverse transcribed into cDNA. PCR was carried out on BeWo cDNA (n=3) with specific primers to detect the expression of TAT1, LAT3 and LAT4 transcripts. Western blotting was carried out to detect the protein expression of TAT1 and LAT4 (LAT3 not tested). BeWo preparations (45 µg protein, n=3) were run on SDS-PAGE gels and transferred to PVDF membranes. Blots were incubated with rabbit anti-TAT1 or anti-LAT4 primary antibody then goat anti-rabbit-HRP secondary antibody. Immunoreactive signals were visualized using enhanced chemiluminescence. The presence of TAT1, LAT3 and LAT4mRNA in BeWo cells was confirmed by PCR. The presence of TAT1 and LAT4 proteins in BeWo cells was confirmed by Western blotting demonstrating antibody specific bands which were not present in the negative control. Immunoblotting for B-actin on each blot indicated similar protein loading in each lane. BeWo cells are placental in origin and commonly used to study human placental function. BeWo cells express the facilitated amino acid transporters at both the mRNA and protein level as seen in human placental tissue. They may therefore provide a useful model for studying the regulation of the facilitated amino acid transporters TAT1, LAT3 and LAT4 in the placenta.