Protein slime

Check out how copper ions interact with proteins from egg white

10 minutes
Experiment's video preview



  • Put on protective gloves and eyewear.
  • Conduct the experiment on the plastic tray.
General safety rules
  • Do not allow chemicals to come into contact with the eyes or mouth.
  • Keep young children, animals and those not wearing eye protection away from the experimental area.
  • Store this experimental set out of reach of children under 12 years of age.
  • Clean all equipment after use.
  • Make sure that all containers are fully closed and properly stored after use.
  • Ensure that all empty containers are disposed of properly.
  • Do not use any equipment which has not been supplied with the set or recommended in the instructions for use.
  • Do not replace foodstuffs in original container. Dispose of immediately.
General first aid information
  • In case of eye contact: Wash out eye with plenty of water, holding eye open if necessary. Seek immediate medical advice.
  • If swallowed: Wash out mouth with water, drink some fresh water. Do not induce vomiting. Seek immediate medical advice.
  • In case of inhalation: Remove person to fresh air.
  • In case of skin contact and burns: Wash affected area with plenty of water for at least 10 minutes.
  • In case of doubt, seek medical advice without delay. Take the chemical and its container with you.
  • In case of injury always seek medical advice.
Advice for supervising adults
  • The incorrect use of chemicals can cause injury and damage to health. Only carry out those experiments which are listed in the instructions.
  • This experimental set is for use only by children over 12 years.
  • Because children’s abilities vary so much, even within age groups, supervising adults should exercise discretion as to which experiments are suitable and safe for them. The instructions should enable supervisors to assess any experiment to establish its suitability for a particular child.
  • The supervising adult should discuss the warnings and safety information with the child or children before commencing the experiments. Particular attention should be paid to the safe handling of acids, alkalis and flammable liquids.
  • The area surrounding the experiment should be kept clear of any obstructions and away from the storage of food. It should be well lit and ventilated and close to a water supply. A solid table with a heat resistant top should be provided
  • Substances in non-reclosable packaging should be used up (completely) during the course of one experiment, i.e. after opening the package.

FAQ and troubleshooting

Any criteria for an egg I should use in this experiment?

Try to select a larger egg: the more egg white is in it, the bigger will be the “slime”.

I can’t get the “slime” out.

Stir the mixture for a little longer to let copper “enter” the egg white. Try your best to stir very carefully, otherwise, you may end up with many small “slimes” instead of a large one.

May I touch the “slime” with my bare (unprotected) hands?

Please do not. The white is covered in copper sulfate that shouldn’t be touched with unprotected hands.

Step-by-step instructions

Prepare the egg white. It consists mostly of water and ovalbumin protein. We won’t need the yolk for this experiment.


Proteins are very complex substances. Their molecules are comprised of thousands of atoms and their properties can change because of even the slightest of chemical or physical impact. Let’s examine how our protein will behave in the presence of our copper salt.


The egg white reacts with copper ions and coagulates! It forms a lump that we can remove from the solution.


Remove excess moisture. You’ve made slime out of stuck together protein molecules.


Expected result

When mixed with copper sulfate, an egg white turns into a bluish slime!


Dispose of solid waste together with household garbage. Pour solutions down the sink. Wash with an excess of water.

Scientific description

How is the slime produced?

Chemically, an egg white is made out of protein molecules. Proteins are very long and complicated molecules, twisted into several spirals, which contain many different segments. These segments are amino acids – organic compounds with carboxyl (–COOH) and amino (–NH2) groups.

Copper sulfate interacts with the amino acids in the protein molecules, with the result that the structure of the protein changes. The protein coagulates and forms a slime.