The invention of the electron microscope brought a great advance in resolution power and allowed research into the ultrastructure of cells and the organelles and other structures within them.
ðɪ ɪnvˈɛnʃən ʌvðɪ ᵻlˈɛktɹɑːn mˈaɪkɹəskˌoʊp bɹˈɔːt ɐ ɡɹˈeɪt ɐdvˈæns ɪn ɹˌɛzəlˈuːʃən pˈaʊɚ ænd ɐlˈaʊd ɹᵻsˈɜːtʃ ˌɪntʊ ðɪ ˌʊltɹɐstɹˈʌktʃɚɹ ʌv sˈɛlz ænd ðɪ ˌɔːɹɡənˈɛlz ænd ˈʌðɚ stɹˈʌktʃɚz wɪðˈɪn ðˌɛm.