Fig. 1.

Delta, Omicron BA.1, and BA.2 differentially infect hiPSC-CMs. Human iPSC-CMs were infected with Delta (D), Omicron BA.1 (O-BA.1) or BA.2 (O-BA.2). A The cells were infected at a multiplicity of infection (MOI) of 1 and were immunostained for virally-encoded nucleocapsid protein (NP) at 24 h post infection (hpi). Graph shows the percentage of NP⁺ hiPSC-CM, n = 4. B Fluorescence images of infected hiPSC-CMs with MOI of 1 at 24 hpi, NP in Red, DAPI in blue. C Replication of SARS-CoV-2 was determined by infecting iPSC-CMs at an MOI of 0.1. The viral titres of supernatant collected at 24, 48, and 72 hpi were determined by plaque assay, n = 3. Data are presented as mean ± SEM, and n refer to biological replicates. Statistical significance was calculated using A one-way ANOVA or C two-way ANOVA with Tukey’s multiple comparisons test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Scale bar = 500 μm