A Rapid Method for Label-Free Enrichment of Rare Trophoblast Cells from Cervical Samples

Bailey-Hytholt CM, Sayeed S, Kraus M, Joseph R, Shukla A, Tripathi A.

Scientific Reports. 2019;9(1):12115. DOI 10.1038/s41598-019-48346-3. PMID 31431640. PMCID PMC6702343.

How to cite

AMA

Bailey-Hytholt CM, Sayeed S, Kraus M, Joseph R, Shukla A, Tripathi A. A Rapid Method for Label-Free Enrichment of Rare Trophoblast Cells from Cervical Samples. Sci Rep. 2019;9(1):12115. doi:10.1038/s41598-019-48346-3

APA

Bailey-Hytholt, C. M., Sayeed, S., Kraus, M., Joseph, R., Shukla, A., & Tripathi, A. (2019). A Rapid Method for Label-Free Enrichment of Rare Trophoblast Cells from Cervical Samples. Scientific Reports, 9(1), 12115. https://doi.org/10.1038/s41598-019-48346-3

BibTeX

@article{baileyhytholt2019rapid,
  title   = {A Rapid Method for Label-Free Enrichment of Rare Trophoblast Cells from Cervical Samples},
  author  = {Bailey-Hytholt, Christina M and Sayeed, Sumaiya and Kraus, Morey and Joseph, Richard and Shukla, Anita and Tripathi, Anubhav},
  journal = {Scientific Reports},
  volume  = {9},
  number  = {1},
  pages   = {12115},
  year    = {2019},
  doi     = {10.1038/s41598-019-48346-3}
}

Fetal cells that carry a baby's entire genome slip into the mother's cervical canal early in pregnancy, offering a route to prenatal testing from a routine Pap sample instead of an invasive procedure. The catch is scale: a single fetal trophoblast can be buried among thousands of maternal cervical cells.

The researchers built a label-free way to concentrate these rare cells, letting a cervical sample settle briefly in a plastic well so the trophoblasts collect on the surface while most cervical cells are poured off. A four-minute settling step removed most of the maternal cells while keeping most of the fetal ones.

The enriched cells were then imaged and picked one at a time, and single cells yielded enough DNA for downstream genetic testing.

Key findings

  • A brief settling step removed most maternal cervical cells while keeping most of the fetal ones. At the optimal 4 min settling time the workflow removed 91 ± 3% of cervical squamous cells while capturing 71 ± 10% of spiked JEG-3 trophoblast cells, a 707 ± 330% enrichment.
  • The fetal and maternal cells differ sharply in size, the physical basis the authors propose for their different settling. JEG-3 trophoblasts measured 13 ± 1 × 11 ± 1 × 8 ± 1.5 μm versus 66 ± 2 × 58 ± 1.5 × 6 ± 1 μm for single cervical cells.
  • Imaging on the CyteFinder confirmed the enrichment, and picked single cells yielded usable DNA. HLA-G staining read on the CyteFinder showed 73 ± 36% JEG-3 capture, and single JEG-3 and trophoblast cells retrieved with the CytePicker produced enough DNA for whole-genome amplification and gender PCR.

CyteFinder in the methods

“RareCyte CyteFinder (RareCyte, Seattle WA) was used to analyze JEG-3 capture and pick individual cells.”

— Bailey-Hytholt et al., Scientific Reports (2019), Materials and Methods, “CyteFinder for trophoblast enrichment analysis”

Why it matters for CyteFinder users

If your work depends on finding and lifting out a handful of rare cells from a crowded background, this study shows the CyteFinder doing exactly that in a setting far from its usual one. The authors first thinned a cervical sample by simple settling, transferred the cells to a slide, and used the CyteFinder to image the whole surface, identify the HLA-G-positive fetal trophoblasts among thousands of maternal cells, and pick individual cells of interest. The rare-cell problem here is fetal, not tumor, but the demand on the instrument is the same one you face: locate a scarce, specifically stained cell and retrieve it intact, without contamination from its neighbors. That the picked single cells then yielded DNA for whole-genome amplification and gender PCR is the proof that matters — image-and-pick is only useful if the cell survives the trip to a tube. For CyteFinder users, the takeaway is that the detect-and-retrieve workflow you rely on for circulating tumor cells generalizes to any rare cell you can stain, which widens where the instrument earns its place.