Biotin Interference in Susceptible CanAg Ca242 Immunoassays and Elimination Method.

BACKGROUND: High-dose biotin therapy is beneficial in progressive multiple sclerosis (MS). Biotin, as dietary supplement or therapy, may lead to analytical interference in biotin-streptavidin immunoassay. METHODS: Seven concentration gradients of biotin solutions were spiked to three different levels of Ca242 serum samples. All samples were tested by CanAg Ca242 ELISA kit to evaluate the interference from biotin. Serum samples with biotin concentration at 1,000 ng/mL were retested after absorption by streptavidin microparticles or direct analysis on the Mindray CL2000i platform. RESULTS: Our study found that CanAg Ca242 is vulnerable to interference when a sample that contains biotin exceeds 15.63 ng/mL. Biotin interference can result in falsely low results in CanAg Ca242. The effect and extent of biotin interference are, to some extent, dependent on the concentration of serum Ca242 and the concentration of biotin. CONCLUSIONS: CanAg Ca242 is vulnerable to biotin interference. The laboratory can overcome biotin interference on CanAg Ca242 by using a non-biotin streptavidin method or by absorbing biotin with streptavidin-coated microparticles before testing. Clinicians should use caution in interpreting abnormal results in patients who ingest biotin.

The bracteatus pineapple genome and domestication of clonally propagated crops.

Domestication of clonally propagated crops such as pineapple from South America was hypothesized to be a 'one-step operation'. We sequenced the genome of Ananas comosus var. bracteatus CB5 and assembled 513 Mb into 25 chromosomes with 29,412 genes. Comparison of the genomes of CB5, F153 and MD2 elucidated the genomic basis of fiber production, color formation, sugar accumulation and fruit maturation. We also resequenced 89 Ananas genomes. Cultivars 'Smooth Cayenne' and 'Queen' exhibited ancient and recent admixture, while 'Singapore Spanish' supported a one-step operation of domestication. We identified 25 selective sweeps, including a strong sweep containing a pair of tandemly duplicated bromelain inhibitors. Four candidate genes for self-incompatibility were linked in F153, but were not functional in self-compatible CB5. Our findings support the coexistence of sexual recombination and a one-step operation in the domestication of clonally propagated crops. This work guides the exploration of sexual and asexual domestication trajectories in other clonally propagated crops.