蛋白质检测，ELISA assay我也做的很多

rt-pcr, ELISA assay 都是最常见的生物学测试。covid test测的是核酸，不是蛋白，和spike 大小没有关系。

在多说一句吧，现在测covid19核酸检测测的一种核鞘蛋白virus nucleocapsid (N)。既不测spike 蛋白也不测S protein的 mRNA

The oligonucleotide primers and probes for detection of 2019-nCoV were selected from regions of the virus nucleocapsid (N) gene. The panel is designed for specific detection of SARS-CoV-2 (two primer/probe sets). An additional primer/probe set to detect the human RNase P gene (RP) in control samples and clinical specimens is also included in the panel.