Moreover, we obtained comparable results on both venous blood and capillary blood samples. Keywords: SARS-CoV-2, COVID-19, Point of care, Lateral circulation immunoassay, Automated chemiluminescent immunoassay, Serological assessments, Laboratory detection Background Coronavirus disease 2019 (COVID-19) is usually a novel coronavirus pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [1, 2]. Emergence of new infectious diseases poses serious clinical issues [3C9], this new contamination was first encountered in December 2019 in Wuhan, Hubei Province, China, and then spread worldwide taking on the appearance of health emergency of international concern. Starting from February 2020, the COVID-19 outbreak spread in Europe, particularly affecting northern Italy and Spain [10C12]. Ctsd World Health Business (WHO), on 11th March 2020 declared COVID-19 disease a global world pandemic. SARS-COV-2 belongs to the beta coronavirus family along NH125 with other human pathogens known as SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-Cov) [13]. As COVID-19 was identified as a health emergency by WHO, large-scale populace screening proved to be of crucially important to identify and isolate symptomatic and asymptomatic case, in the global efforts to contain its growth. In December 2019, SARS-COV-2 was firstly transmitted to humans through human-animal contact at live animals market in Wuhan (China) [14]. SARS-CoV-2 belongs to the subfamily of the Coronavirinae, which is usually part of the order Nidoviralescoronaviruses. It is a single-stranded RNA-enveloped computer virus, made up of 4 structural proteins (from your 3end open reading frames- ORF) and 16 accessory proteins (nsp 1 to nsp 16) from your NH125 5end ORFs. The viral envelop contains structural proteins E and M, while the N protein nucleocapsid binds the viral RNA. The S glycoprotein is the important player for the conversation with?angiotensin-converting enzyme 2 (ACE2) around the host cells (Fig.?1) [15]. The conversation between ACE2 and the S glycoprotein was conserved also in the SARS-CoV, the computer virus responsible of the SARS outbreak of 2002C2003. The S protein binds to the receptor to target host organism cells. The computer virus uses also other host cell receptors such as the type 2 transmembrane serine protease (TMPRSS2), to trigger the endocytotic process employed to access the cells [16]. Viral polyproteins are expressed in the host cell, RNA can be synthetized via its RNA-dependent RNA polymerase and new viral particles can be produced and released. Open in a separate windows Fig. 1 Spike protein of the SARS-CoV-2. a, b 3D structure of the Spike protein in the cleaved (a) or uncleaved (b) conformations (EMDB-11205, PDB 6ZGG or EMDB-11203, PDB 6ZGE respectively). Panel a also indicates Furin cleavage site Cleavage NH125 at the S1/S2 and the S2 site of the S protein by the proteases of the host cell is necessary for membrane fusion [17] (Fig.?2). Cleaved S protein is usually therefore the activated form ready to enter the cell. This proteolytic step can also occur in the constitutive secretory pathway of infected cells by endosomal cathepsins B and L and furin [18]. Here, the viral membrane the S protein can be cleaved (primed) in two segments (Fig. ?(Fig.2).2). The N-terminal S1 segment is responsible for the interaction with the host cell receptor, as it contains a signal peptide and the receptor binding domain name (RBD). The S2 segment anchors the S protein to the viral membrane, contains the fusion peptide which mediates the fusion of the viral membrane with the plasma membrane of the target cell. The proteases responsible for the S protein activation represent encouraging drug targets for the treatment of the disease, following failure of first attempts, such as hydroxychloroquine [19]. Open in a separate windows Fig. 2 Structure and domain name organization of the Spike protein of the SARS-CoV-2. a The S1 subunit includes the RBD, which is responsible for the interaction with the ACE2 receptor around the host cell membrane. The subunit S2 includes the membrane fusion complex (fusion peptide, heptad repeats HR 1 and HR2), anchors the S2 subunits to the viral membrane with its transmembrane domain name, and interacts with the viral ribonucleoprotein complex through its endodomain. b D614G mutation in the Spike protein and frequency across.