Fully automated dried blood spot sample handling and extraction for serological testing of SARS‐CoV‐2 antibodies

Abstract

At the beginning of 2020, an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reached pandemic dimensions. Throughout the event, diagnostic tests function as an essential tool for understanding, mitigating, and implement strategies to curb and reduce infections. Here, we present a novel method for the fully automated dried blood spot (DBS) sample handling and extraction for serological testing of human IgG antibodies against SARS-CoV-2 using a commercial enzymelinked immunosorbent assay (ELISA) testing kit. This proof-of-principle pilot study successfully demonstrates the recovery of antibodies in their intact form from DBS using automated, direct sample elution within 100 μl of extraction buffer. The use of minimally invasive DBS sampling provides an alternative to existing analytical procedures such as sampling by venipuncture or nasal swabs. Due to the ease of DBS collection, no third party need be involved, making at-home sampling possible (e.g., during quarantine).

Use of dried blood spot samples for SARS-CoV-2 antibody detection using the Roche Elecsys ® high throughput immunoassay

“…When considering large-scale DBS testing programmes, additional factors which might impact on programme success include the more complex processing of DBS samples relative to plasma samples upon arrival in the testing laboratory. However, this may not be a substantial barrier as options for automation have been presented by Gaugler et al [ 26 ].…”

Evaluation of Dried Blood Spot Testing for SARS-CoV-2 Serology Using a Quantitative Commercial Assay

“…DBS specimens have been shown to be stable at room temperature, 4 °C and −20 °C, at ambient or low humidity conditions for at least 28 days [ 26 ]. An automated DBS extraction procedure is also being developed [ 23 ].…”

“…These assays have demonstrated high specificity and sensitivity using serum/plasma. Although there have been preliminary studies evaluating DBS collection for anti-SARS-CoV-2 immunoassays, DBS serology tests have yet to be used on a widespread scale [ 2 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Importantly, the majority of platforms evaluated have been for qualitative assays for antibodies against SARS-CoV-2, a potential gap should a quantitative option prove beneficial.…”

Analysis of SARS-CoV-2 antibodies from dried blood spot samples with the Roche Elecsys Immunochemistry method

“…Our study was aimed at validating this strategy with Roche automated instruments for high volume analysis using a qualitative nucleocapsid assay. This approach has several advantages over ELISA methods, even when the sample preparation procedure is automated [ 12 ]. Moreover, Roche systems are available worldwide in many central laboratories, and dried blood spot analysis does not require any modification to instrument parameters or reagents.…”