Alexa fluor488 donkey anti rabbit igg h l secondary antibody

After cultivation under differentiation media in petridish (Thermofisher brand) for 7 days, the UCMSCs in the tissue culture plates (TCPs), GelMA-O5 and GelMA-O5/rGO hydrogels were fixed in 4% cold paraformaldehyde aqueous solution at room temperature for 10 min. The culture medium was changed every three days. After being rinsed for three times with PBS, the gels placed overnight in a 30% (w/v) sucrose in PBS solution at 4 °C. The gels were frozen at −20 °C and cut into sections with a thickness of 20 μm. After blocking with 1% bovine serum albumin (BSA)/PBS at room temperature for 30 min, the samples were incubated with the primary antibody rabbit anti-cardiac troponin I (cTnI, ab47003, abcam, 1: 100) and rabbit anti-connexin 43 (Cx43, ab11370, abcam, 1: 100) in 1% BSA overnight at 4 °C. After being washed with PBS for several times, the samples were incubated with an Alexa Fluor488 Donkey anti-rabbit IgG (H&L) secondary antibody (A11034; Invitrogen, 1: 500) for cTnI detection in PBS for 1 h. After being rinsed with PBS, further stained with DAPI and then imaged using the confocal laser microscope (Olympus FV1000, Tokyo, Japan).