Traube cell

How to grow chemical algae

Want to find out how easy it is to grow an ar­ti­fi­cial cell with just two salts? Check this out!

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion.


  • cop­per(II) sul­fate so­lu­tion;
  • potas­si­um hex­a­cyano­fer­rate(II) tablets;
  • cu­vette.

Step-by-step in­struc­tions

Fill a cu­vette with a so­lu­tion of cop­per(II) sul­fate and add a few tablets of potas­si­um hex­a­cyano­fer­rate(II). Af­ter a while, ob­serve the growth of ar­ti­fi­cial cells!

Process de­scrip­tion

Potas­si­um hex­a­cyano­fer­rate(II) re­acts with cop­per(II) sul­fate to form a “cell” with a film of cop­per(II) hex­a­cyano­fer­rate(II). This film has one in­ter­est­ing prop­er­ty – it will al­low wa­ter mol­e­cules, but not cop­per(II) sul­fate, to pass through it. Such films are called “semi-per­me­able,” since they al­low some sub­stances to pass through but re­tain oth­ers. The con­cen­tra­tion of potas­si­um hex­a­cyano­fer­rate(II) in­side the "cell" is greater than the con­cen­tra­tion of cop­per(II) sul­fate out­side the “cell,” and there­fore wa­ter dif­fus­es through the film into the "cell" un­til the con­cen­tra­tions of potas­si­um hex­a­cyano­fer­rate(II) and cop­per(II) sul­fate are equal­ized. The in­flux of wa­ter tears the film, and a new film forms at the site of the tear! In­ter­est­ing­ly, plant cell mem­branes pos­sess a sim­i­lar abil­i­ty to se­lec­tive­ly al­low sub­stances through.

Per­form more cool and safe ex­per­i­ments with our MEL Chem­istry sub­scrip­tion!