Dried blood spots are an efficient blood sampling method for the detection of SARS-CoV-2 antibodies

Abstract

A novel coronavirus termed SARS-CoV-2 caused an outbreak in December of 2019 which has led to pandemic. Currently several serological diagnostic assays exist for the detection of SARS-CoV-2, which require the collecting of whole blood that brings about problems including the invasive nature of venepuncture, poor acceptance by patients and their storage and transportation. A more fast, efficient and less tedious method that allows mass blood sampling is necessary during a pandemic to quickly diagnose disease and obtain population serological data. Dried blood spot (DBS) sampling has been used for several decades for the accurate detection of viral specific antibodies and remains one the most convenient methods for obtaining serological data on exposed patients. Here we evaluate the use of DBS sampling on current viral serological assays including SARS-CoV-2. DBS samples were collected from six patients (five control and one positive for SARS-CoV-2 infection) and patient serum was extracted and tested blindly using commercially available antibody test kits for Coxiella burnetti, parvovirus B19 and SARS-CoV-2. The results demonstrate that antibodies recovered from DBS after elution are comparable to those found in serum, indicating that serological tests can be adapted to test DBS samples from patients using our modified protocol. Because DBS sampling is a much faster and cheaper method of sampling blood, this modification could therefore allow for potential nationwide testing for epidemiological studies.