FISH Analysis of Sorted Nucleated Erythroid Cells
| Sample . | Fetal Karyotype by CAAF . | No. of Cells Sorted . | No. of Cells Examined by FISH . | No. of Cells With XY Signal . | Hybridization Efficiency* X/Y/21 Probe (%) . | Fetal Sex Correctly Assigned by FACS/FISH . |
|---|---|---|---|---|---|---|
| 1 | 46,XY | 48,700 | 125 | 7 | 31/78 | Y |
| 13 | 46,XY | 12,019 | 952 | 10 | 71/95 | Y |
| 15 | 46,XY | 52,134 | 60 | 2 | 85/94 | Y |
| 18 | 46,XY | 2,978 | 12 | 1 | 79/95 | Y |
| 24 | 46,XY | 3,174 | 99 | 4 | 68/89 | Y |
| 25 | 46,XY | 963 | 145 | 14 | ND/80 | Y |
| 26† | 46,XY | 11,679 | 84.9 | 0 (n = 13) | 65.3/87.9 | N |
| 6 | 46,XX | 7,432 | 99 | 5 | 78/89 | N |
| 16 | 46,XX | 4,368 | 142 | 0 | 93/91 | n/a |
| 19 | 46,XX | 4,411 | 72 | 0 | 75/73 | n/a |
| 20 | 46,XX | 10,439 | 1,727 | 9 | 75/72 | N |
| 21 | 46,XX | 18,500 | 2,423 | 0 | 59/92 | n/a |
| 27 | 46,XX | 1,900 | 277 | 0 | 79/89 | n/a |
| 28 | Nongravida control | 9,808 | 51 | 0 | 71/89 | n/a |
| 29 | Nongravida control | 106,000 | 51 | 0 | 69/72 | n/a |
| 30 | Nongravida control | 16,200 | 149 | 1 | 78/86 | n/a |
| 31 | Nongravida control | 20,100 | 72 | 1 | 59/84 | n/a |
| 42 | 47,XY,+21 | 18,000 | 0 | 0 | 79/84/60 | N |
| 43 | 47,XY,+21 | 19,000 | 24 | 3 | 90/92/60 | Y |
| 44 | 47,XY,+21 | 5,200 | 856 | 2 | 77/85/53 | Y |
| 45 | 47,XY,+18 | 1,300 | 423 | 0 | 68/89 | N |
| Sample . | Fetal Karyotype by CAAF . | No. of Cells Sorted . | No. of Cells Examined by FISH . | No. of Cells With XY Signal . | Hybridization Efficiency* X/Y/21 Probe (%) . | Fetal Sex Correctly Assigned by FACS/FISH . |
|---|---|---|---|---|---|---|
| 1 | 46,XY | 48,700 | 125 | 7 | 31/78 | Y |
| 13 | 46,XY | 12,019 | 952 | 10 | 71/95 | Y |
| 15 | 46,XY | 52,134 | 60 | 2 | 85/94 | Y |
| 18 | 46,XY | 2,978 | 12 | 1 | 79/95 | Y |
| 24 | 46,XY | 3,174 | 99 | 4 | 68/89 | Y |
| 25 | 46,XY | 963 | 145 | 14 | ND/80 | Y |
| 26† | 46,XY | 11,679 | 84.9 | 0 (n = 13) | 65.3/87.9 | N |
| 6 | 46,XX | 7,432 | 99 | 5 | 78/89 | N |
| 16 | 46,XX | 4,368 | 142 | 0 | 93/91 | n/a |
| 19 | 46,XX | 4,411 | 72 | 0 | 75/73 | n/a |
| 20 | 46,XX | 10,439 | 1,727 | 9 | 75/72 | N |
| 21 | 46,XX | 18,500 | 2,423 | 0 | 59/92 | n/a |
| 27 | 46,XX | 1,900 | 277 | 0 | 79/89 | n/a |
| 28 | Nongravida control | 9,808 | 51 | 0 | 71/89 | n/a |
| 29 | Nongravida control | 106,000 | 51 | 0 | 69/72 | n/a |
| 30 | Nongravida control | 16,200 | 149 | 1 | 78/86 | n/a |
| 31 | Nongravida control | 20,100 | 72 | 1 | 59/84 | n/a |
| 42 | 47,XY,+21 | 18,000 | 0 | 0 | 79/84/60 | N |
| 43 | 47,XY,+21 | 19,000 | 24 | 3 | 90/92/60 | Y |
| 44 | 47,XY,+21 | 5,200 | 856 | 2 | 77/85/53 | Y |
| 45 | 47,XY,+18 | 1,300 | 423 | 0 | 68/89 | N |
PB (n = 33) was drawn at 10-13 weeks' gestation before any invasive diagnostic procedure, density separated, and frozen until future use. After sorting, cells (except sample 1) were cultured for either 18 hours or 5 days in serum-free media Epo, MGF, IL-6, GM-CSF/IL-3 fusion protein, M-CSF, and Flt-3 ligand (samples 27, 44 and 45 only) and the results from both cultures were pooled. FISH was performed without previous knowledge of the fetal karyotype.
Abbreviations: n/a; not applicable; CAAF, cytogenetic analysis of amniotic fluid; ND, not determined.
Hybridization efficiency was controlled in each experiment using pure male and female mononuclear cells.
Mean values for all maternal PB samples in which there were no XY cells found.