Chemistry of Biotin–Streptavidin and the Growing Concern of an Emerging Biotin Interference in Clinical Immunoassays

Abstract

Overconsumption of biotin (5−100 mg daily) as a supplement by the general population poses a significant problem for clinical immunoassays (IAs) based on biotin−streptavidin (SA) interactions. This affinity pair has been exploited in immunoassays because of its avidity, sensitivity, specificity, and stability. The elevated biotin level in plasma varies from patient to patient, and its severe interference cannot easily be predicted and quantified. Thus, immunoassay manufacturers must investigate the biotin interference in the developed immunoassays to satisfy the threshold of 3510 ng/mL (14 367 nM), as stipulated by the FDA. There is no concrete solution to circumvent the biotin interference without extra costs and technical difficulties, albeit different strategies have been attempted. They include the IA format with biotinylated reagents prebound to streptavidin, the removal of biotin from the specimen, sample treatment, and biotin interference-free assays. The general public has been instructed to stop taking biotin supplements for 48 h or even weeks before the test, depending on the specific test, dose, and frequency of biotin uptake. As lab-based techniques cannot accommodate an enormous number of public samples, a rapid analytical procedure for biotin is urgently needed to quantify for its interference in immunoassays.

Diverse high-affinity DNA aptamers for wild-type and B.1.1.7 SARS-CoV-2 spike proteins from a pre-structured DNA library

“…The second biotinylated MSA1 aptamer was tagged with horseradish peroxidase (HRP) conjugated to streptavidin. Formation of the biotin-streptavidin conjugate prior to the assay avoids the potential for interference by endogenous biotin in clinical samples, which has been reported in some ELISA assays ( 50 ). The presence of the PV led to immobilization of HRP onto the plate, which oxidized 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H 2 O 2 .…”

Key Points of Technical Review for the Registration of Sars-Cov-2 Antigen/Antibody Tests

“…The potential highest concentration of interfering substances (regarded as ‘worst case’ conditions) and the weak positive concentration of virus antigen and antibody are recommended for the interference evaluation. If streptavidin–biotin system is used for the assay, the interference of free biotin in samples [ 42 , 43 ] should be analyzed carefully.…”

The biotin interference within interference suppressed immunoassays

“…The intake of biotin supplements has increased significantly in the recent years 1‐3 . According to current research, biotin is known to cause interference in immunoassays 4‐6 .…”

“…A biotin intake of 0.03–0.06 mg/day is recommended for adults, while the recommended intake for children and adolescents is significantly lower 2,6,8,10,14 . A balanced diet without caloric restriction basically ensures a sufficient biotin intake 1,2 . A biotin deficiency occurs with healthy humans only very rarely and usually takes place in pregnancy 2,4,8,15,16 .…”