Dynamic Change Process Of Target Genes By RT-PCR Testing Of SARS-Cov-2 During The Course Of A Coronavirus Disease 2019 Patient

Clinica Chimica Acta
Volume 506, July 2020, Pages 172-175

Lv, Ding-feng; Ying, Qi-ming; Weng, Yue-song; Shen, Chi-bin; Chu, Jin-guo; Kong, Jing-ping; Sun, Ding-he; Gao, Xiang; Weng, Xing-bei; Chen, Xue-qin.

Abstract

We report the dynamic change process of target genes by RT-PCR testing of SARS-Cov-2 during the course of a COVID-19 patient: from successive negative results to successive single positive nucleocapsid gene, to two positive target genes (orf1ab and nucleocapsid) by RT-PCR testing of SARS-Cov-2, and describe the diagnosis, clinical course, and management of the case. In this case, negative results of RT-PCR testing was not excluded to diagnose a suspected COVID-19 patient, clinical signs and symptoms, other laboratory findings, and chest CT images should be taken into account for the absence of enough positive evidence. This case highlights the importance of successive sampling and testing SARS-Cov-2 by RT-PCR as well as the increased value of single positive target gene from pending to positive in two specimens to diagnose laboratory-confirmed COVID-19.

Keywords

Coronavirus, SARS-Cov-2, COVID-19, RT-PCR testing, Nucleocapsid

Isolation and identification of an scFv antibody against nucleocapsid protein of SARS-CoV

Microbes and Infection
Volume 9, Issue 8, July 2007, Pages 1026-1033

Aizhi Zhao, Weijun Qin, Yueheng Han, Weihong Wen, Wenhong Zhang, Zhonghui Lian, Gang Chen, Zhuoli Zhang, Jianqiang Peng, He Wang, Yinglu Guo.

Abstract

To develop reagents for early diagnosis and therapeutic drugs against SARS-associated coronavirus (SARS-CoV), a large (3 × 109) immunized human antibody library was constructed from peripheral blood mononuclear cells from six SARS convalescent patients. A single chain variable fragment antibody (N18) with high affinity against N protein of SARS-CoV was isolated. Sequence analysis revealed that the VL gene was composed of VL3 h (V lambda subgroup) and JL2 regions and the VH gene was composed of VH1-69 (VH1 subgroup), D2-15, D3-22 and JH6 regions. Soluble N18 antibody was expressed in Escherichia coli HB2151, purified by Ni–NTA affinity chromatography and verified by SDS-PAGE and Western blot. The potential application for early diagnosis was evaluated using N protein capture ELISA in which N18 antibody demonstrated high sensitive activity in detecting N protein of SARS-CoV. Finally, the potential usefulness of the N18 antibody in prophylaxis, vaccine design and therapy of SARS is discussed.

Keywords

SARS-CoV, scFv, Nucleocapsid, Phage display