Hemoglobin constant spring can interfere with glycated hemoglobin measurements by boronate affinity chromatography.

the online Data Supplement). The fetal-specific allele was positively detected in 36 of the 41 SABER analyses in which the fetal genotype was informative (Table 1). When applied as a panel, the assays were able to detect the presence of the paternally inherited, fetal-specific allele in at least one of the informative SNPs in all of the cases (Table 1). There was no false-positive detection. In summary, we have developed a panel of 9 SNPs to serve as positive controls for circulating fetal DNA. Additional SNPs could be added to increase the informative rate of the panel. Alternatively, placental epigenetic signatures could also serve such a purpose (5 ). Because the latter approach is not polymorphism based, it negates the need to determine the fetomaternal genotypes, but the epigenetic approach relies on bisulfite modification, which enhances the technical complexity of the analysis. The availability of both genetic and epigenetic fetal DNA controls would allow individual laboratories to choose the technology platform(s) that would be most easily implemented for their expertise.