Role of Triton X-100 in chemiluminescent enzyme immunoassays capable of diagnosing genetic disorders

• Published in: Talanta (Oxford) 2013-11, Vol.116, p.403-408
• Main Authors: Chong, Richard, Rho, Jee-Eun R., Yoon, Hye-Joo, Park, Paul S., Rho, Tae-Ho D., Park, Jee Y., Park, Lucienne, Kim, Young-Hwan, Lee, Ji Hoon
• Format: Article
• Language: English
• Subjects: 1,1′-Oxalyldiimidazole chemilumescence; alpha-Fetoproteins - genetics; alpha-Fetoproteins - metabolism; Calibration; chemiluminescence; Chemiluminescent enzyme immunoassay; Chorionic Gonadotropin - blood; Chorionic Gonadotropin - genetics; Chromosomes, Human, Pair 18 - genetics; Chromosomes, Human, Pair 18 - metabolism; cost effectiveness; Down Syndrome - diagnosis; Down Syndrome - genetics; Down Syndrome - metabolism; enzyme immunoassays; estriol; Estriol - blood; Estriol - genetics; Fetus; fluorescent dyes; Gender disorders; genetic disorders; Genetic Testing; Horseradish Peroxidase - chemistry; human chorionic gonadotropin; Humans; Hydrogen Peroxide - chemistry; hydrophilicity; Hydrophobic and Hydrophilic Interactions; hydrophobicity; Imidazoles - chemistry; Immunoenzyme Techniques; Limit of Detection; Luminescent Measurements; octoxynol; Octoxynol - chemistry; Oxazines - chemistry; peroxidase; Peroxyoxalate; surfactants; trisomics; Trisomy - diagnosis; Trisomy - genetics; Trisomy 18 Syndrome; Triton X surfactants
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2013.06.008

The use of Triton X surfactants in developing 1,1′-oxalylimidazole chemiluminescent enzyme immunoassays (ODI CEIs) with extended linear response range for the quantification of unconjugated estriol (uE3), alpha-fetoprotein (AFP), and human chorionic gonadotropin (hCG) is reported for the first time. The wider linear dynamic range in ODI CLEIA results from Triton X series (e.g., Triton X-100, -114, -405, -705) acting as an inhibitor in the interaction between Amplex Red (hydrophobic substrate) and horseradish peroxidase (hydrophilic enzyme) to produce resorufin (hydrophobic fluorescent dye). Triton X-100 acts as the appropriate inhibitor in ODI CLEIA. The maximum concentrations of AFP and hCG quantified with sandwich ODI CLEIA in the presence of Triton X-100 were 8 times higher than when analyzed with the same system in the absence of Triton X-100. In addition, the lowest concentration of uE3 determined using competitive ODI CLEIA in the presence of Triton X-100 was 20 times lower than that measured with competitive ODI CLEIA in the absence of Triton X-100. These results indicate that rapid quantification of AFP, uE3, and hCG using cost effective and highly sensitive ODI CLEIAs in the presence of Triton X-100 can be applied as an accurate, precise, and reproducible method to diagnose genetic disorders (e.g., trisomy 18 and trisomy 21) in fetuses. •Using shielding/sequestering effect of Triton X-100 micelles on the reaction between hydrophobic molecules (e.g., Amplex Red) and hydrophilic molecules (e.g., HRP), competitive and sandwich 1,1′-oxalyldiimidazole enzyme immunoassays were developed for the diagnosis of genetic disorders.•Trace levels of uE3 were quantified using competitive ODI CLEIAs in the presence of 0.1wt% Triton X-100.•Sandwich ODI CLEIA in the presence of 0.1wt% Triton X-100 can quantify high concentration of target markers that cannot be quantified using conventional EIAs, including ODI CLEIA, in the absence of Triton X-100.