cell science - Timeline

Jansen invents microscope

Hooke discovered cells

Leeuwenhoek discovered protozoa and bacteria 9 years later

Brown described the cell nucleus

Schleiden and Schwann proposed cell theory

Albrecht von Roelliker discovered sperm cells and egg cells are cells

N. Pringsheim discovered how a sperm cell penetrated an egg cell

Rudolph Virchow discovers cells come from existing cells

Kolliker described mitochondria

Flemming described chromosome behavior during mitosis

Germ cells are haploid, chromosome theory of heredity

Golgi described the golgi apparatus

Behrens used differential centrifugation to separate nuclei from cytoplasm

Siemens produced the first commercial transmission electron microscope

Gey and coworkers established a continuous human cell line

Eagle systematically defined the nutritional needs of animal cells in culture

Meselson, Stahl and Vinograd developed density gradient centrifugation in cesium chloride solutions for separating nucleic acids

Ham introduced a defined serum-free medium. Cambridge Instruments produced the first commercial scanning electron microscope

Sato and colleagues publish papers showing that different cell lines require different mixtures of hormones and growth factors in serum-free media

Transgenic mice and fruit flies are produced. Mouse embryonic stem cell line established

Tsien identifies mutant of GFP with enhanced spectral properties

Mice are cloned from somatic cells

Hamilton and Baulcombe discover siRNA as part of post-transcriptional gene silencing in plants