Lentivirus

GCaMP is a genetically encoded calcium indicator (GECI) and created from a fusion of green fluorescent protein (GFP), calmodulin (CaM), and M13, a peptide sequence from myosin light chain kinase. When GECI binds Ca2+, the conformational change of GCaMP induces proximity of the GFP parts, eliciting strong GFP fluorescence signal, which allows measuring action potentials and other receptor activation events that trigger Ca2+ influx. The advantage of GECI's are that they can be genetically specified for studies in living organisms. GCaMP6 is a novel ultra-sensitive format of GCaMP that outperformed other sensors in terms of accuracy and sensitivity in measuring cytosol Ca2+ level. Mutations in calmodulin part of GCaMP6 created several variants which showed different calcium fluorescence decay rate (fast - GCamP6f, slow - GCaMP6f and medium - GCaMP6m).

The pandemic coronavirus disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). As the first step of the viral replication, the virus attaches to the host cell surface before entering the cell. The viral Spike protein recognizes and attaches to the Angiotensin-Converting Enzyme 2 (ACE2) receptor found on the surface of type I and II pneumocytes, endothelial cells, and ciliated bronchial epithelial cells. Drugs targeting the interaction between the Spike protein of SARS-CoV-2 and ACE2 may offer protection against the viral infection. Omicron Variant was identified in South Africa in November of 2021. This variant has a large number of mutations that allow the virus to spread more easily and quickly than other variants. As of May 2022, Omicron variants were divided into seven distinct sub-lineages: BA.1, BA.1.1, BA.2, BA.3, BA.2.12.1, BA.4, and BA.5. As of October 2022, several new BA.5 sub-lineages (e.g. BQ.1, BQ.1.1, BF.7) have been designate