Rabbit anti mouse cy3

Following 3 washes with PBS, cells (plated on a 1 × 1 cm glass slide) were fixed for 20 min with 4% paraformaldehyde and washed again with PBS. The samples were then incubated for 10 min at room temperature with 0.5% Triton X-100 in PBS and blocked with 5% bovine serum albumin (BSA) in PBS for 30 min at room temperature. Primary antibodies were diluted in 5% BSA in PBS and incubated overnight at 4 °C. Following 3 washes with 0.5% Triton X-100 in PBS, the samples were incubated with secondary antibodies diluted in 5% BSA for 60 min at 37 °C. The samples were then washed, incubated with Hoechst 33342 (Beyotime, China) in PBS for 30 min at 37 °C and washed again before imaging. Immunofluorescence staining was imaged using an A1R confocal microscope (Nikon, Japan). The following antibodies were used in this study: anti-SOX2, anti-Nanog (Proteintech, China), anti-cTnT, anti-CX43 (Abcam, China), and anti-α-actinin (Proteintech, China). The secondary antibodies were goat anti-rabbit Cy3, rabbit anti-mouse Cy3 (CWBIO, Beijing, China), and goat anti-rabbit 488 (ZSGB-Bio, Beijing, China). Sarcomere lengths and nuclear numbers were measured by ImageJ software. n > 10 cells per condition, three biological replicates. The lengths of ten sarcomeres from each cell were measured and averaged for each condition.