Development and validation of a simple HPLC-MS/MS method for the quantification of methylmalonic acid in human serum without a derivatization step.

A simple and rapid HPLC-MS/MS analytical method was developed and validated for the determination of methylmalonic acid (MMA) in human serum without a derivatization step. Serum samples (200 μl) were pretreated using a simple method based on ultrafiltration using a VIVASPIN 500 ultrafiltration column. Chromatographic separation was achieved on a Luna Omega C18 column with a PS C18 precolumn guard by gradient elution using 0.

SARS-CoV-2 rapid antigen testing in the healthcare sector: A clinical prediction model for identifying false negative results.

Objectives: SARS-CoV-2 rapid antigen tests (RAT) provide fast identification of infectious patients when RT-PCR results are not immediately available. We aimed to develop a prediction model for identification of false negative (FN) RAT results.

Methods: In this multicenter trial, patients with documented paired results of RAT and RT-PCR between October 1 2020 and January 31 2021 were retrospectively analyzed regarding clinical findings.