Skip to content



  • Wool pretreatment
  • Chemical dissolution
  • Filtration
  • Centrifugation
  • Biuret reagent
  • Dialysis
  • Freeze-drying


Timing Difficulty Safety
25 h Low Low


  • OPTION 01: Soxhlet extraction set, measuring cups, spoon, oven, plastic bags
  • OPTION 02: Lab padder, lab press, measuring cups, spoon, oven, plastic bags


  • OPTION 03: Cooking roller, heatpress, dehydrator / oven, measuring cups, spoon, plastic bags (zipper)


a. b. c.
Acetone / Ethanol Distilled Water Wool
200 ml 50 ml 50 g
  • You can reuse the concentration.

Materials description


Acetone, propanone or dimethyl ketone, is an organic compound with the formula C3H6O. It is a colourless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscible with water and serves as an important organic solvent in its own right, in industry, home, and laboratory.

Chemical formula Melting point Molar mass Density Appearance Solubility in water
C3H6O -95°C 58,08 g/mol 784 kg/m³ colourless liquid miscible

is an organic chemical compound. It is a simple alcohol with the chemical formula C2H6O. Ethanol is a volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. Ethanol is naturally produced by the fermentation of sugars by yeasts or via petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the synthesis of organic compounds. Ethanol is a fuel source.

Chemical formula Melting point Molar mass Density Appearance Solubility in water
C2H6O −114.14 ± 0.03°C 46.069 g·mol−1 0.78945 g/cm³ colourless liquid miscible


  • Clean the wool with acetone or ethanol mixture solvent in Soxhlet extraction set for 48 h.
  • Then rinse it in distilled water and dry at 100°C for 12 h in an oven.
  • x


Timing Difficulty Safety
6 - 24 h Medium High

Important facts

  • pH
  • Temperature
  • Time


  • preheating magnetic stirrer, protective gloves, protective glasses, lab coat, measuring cups (lab), magnet, weight, spoon, funnel, kettle

Materials description


also known as carbamide, is an organic compound with chemical formula CH₄N₂O. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry.

Chemical formula Melting point Molar mass Density Systematic name Appearance Solubility in water
CH₄N₂O 182 °C 76,12 g/mol 1.32 g/cm³ thiokarbonyldiamid white solid 545 g/L (at 25 °C)


Sodium bisulfate is an acid salt formed by partial neutralization of sulfuric acid by an equivalent of sodium base, typically in the form of either sodium hydroxide (lye) or sodium chloride (table salt).

Chemical formula Melting point Molar mass Density Appearance Solubility in water
NaHSO₄ 58.5°C 120.06 g/mol (anhydrous); 138.07 g/mol (monohydrate) 2.742 g/cm3 (anhydrous); 1.8 g/cm3 (monohydrate) white solid 28.5 g/100 mL (25 °C) ; 100 g/100 mL (100 °C)

caustic soda - is an inorganic compound with the formula NaOH. It is a white solid ionic compound. Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner.

Chemical formula Melting point Molar mass Density Appearance Solubility in water
NaOH 323°C 39.9971 g mol−1 2.13 g/cm³ white, hard (when pure), opaque crystals 418 g/L (0 °C); 1000 g/L (25 °C); 3370 g/L (100 °C)


a. b. c. d. e.
Urea M-bisulfite NaOH Distilled Water Wool
8 % 0,5 % 1 % 90,5 % -
54 g 3 g 6 g 600 ml 10 g


  • x


a. Initial quantity b. Extracted c. Filtrated
600 ml 300 ml 290 ml


Timing Difficulty Safety
1 h Low Low
  • What is it?


  • paper filters (better folded ones - coffee filters did not work out in this case), lab glass jar, funnel


  • How it works?


Timing Difficulty Safety
15-20 min Low Medium
  • What is it?


  • lab tubes for centrifugation (25 ml with a cover), drill, 3D printed holder, screws, protective glasses, syringe


  • How it works?


  • You have to properly stabilize the 3D print to the drill - avoid excessive torque. The lab tubes must be properly stabilized.


Timing Difficulty Safety
1 - 48 h Medium Low


  • weight, measuring cups, spoon, cokng stove / oven, 2 x cooking pots, paper filters, plate (for crystallzation), spoon, bottle (for the biuret solution), kettle

Composite of Biuret reagent

a. b. c. d.
Copper sulphate Sodium potassium tartarate (Rochelle salt) NaOH Distilled water
1,5 g 6 g (in 500 ml of water) 23,4 g 1 l
  • Copper sulphate
Chemical formula Melting point Molar mass Density Appearance Solubility in water
CuSO₄ 110°C 159,609 g/mol 3.60 g/cm³ grey-white, blue 1.055 molal (10 °C)
  • Sodium potassium tartarate - Rochelle salt
Chemical formula Melting point Molar mass Density Appearance Solubility in water
KNaC₄H₄O₆·4H2O 75°C 282.1 g/mol 1.79 g/cm³ Colorless, odorless monoclinic needles 26 g/100 mL (0°C); 66 g /100 mL(26°C)
  • Cream of tartar

Potassium bitartrate - also known as potassium hydrogen tartrate, is a byproduct of winemaking. In cooking, it is known as cream of tartar. It is processed from the potassium acid salt of tartaric acid. The resulting powdery base can be used in baking or as a cleaning solution (when mixed with an acidic solution such as lemon juice or white vinegar).

Chemical formula Melting point Molar mass Density Appearance Solubility in water
KC₄H5O₆ - 188.177 g/mol 1.05 g/cm³ (solid) White crystalline powder 0.57 g/100ml (20°C)

In case that you do not have sodium potassium tartarate called also Rochelle salt, you can do it on your own. Following the recipe below.


  • Mix the copper sulphate with Rochelle salts in 500 ml of cold distilled water. Till it will completely disolved.
  • Beside prepare solution of Sodium hydroxide - 2 Ml of NaOh : 375 ml of distilled water (hot).

    1 L of 2.00 M NaOH solution contains 2.00 x (23.0 + 16.0 + 1.0) g NaOH --> 500 ml of 2.00 M NaOH solution contains 80 / 2 g NaOH = 40.0 g of NaOH

  • Let the soluion of sodium hydroxid to cool down.
  • Mix both the solution NaOH and copper sulphate in volumetric flask and make it final volume to 1000 ml by adding distilled water.

Composite of Rochelle salts

  • If you start with 500 g of baking soda or washing soda and 200 g of cream of tartar, you should collect around 210 grams of Rochelle salt.
a. b. c.
Baking soda or Washing soda Cream of tartar Distilled water (hot)
500 g 145 g 200 ml


  • Place a pot on a cooking stove on the highest temperature and add baking soda. Keep stirring for 20-30 min.
  • Let the baking soda cool down and in the meantime prepare solution of cream of tartar.
  • Place one pot with water on the cooking stove and add a glass jar into it - to create a bath. Pour destilled water into the jar and preheat it a little.
  • After you can slowly add the cream of tartar. Stir it properly.
  • One by one with a spoon add the baking soda into the pot. A chemical reaction will appear. Do it slowly and wait till the reaction will sttol tto add another spoon.
  • Add more baking soda till you will see that no reaction appears again. What means that the solution is "full enough".
  • Also the white creamy solution of the cream of tartar will become transparent.
  • Filter the solution through a coffee filter and the rest pour into a flat pan or plate to crystallize. Do not forget to cover it with a piece of ppaper to avoid dust.
  • Usually it takes 2 days to grow crystals.
  • After you can dry them naturally or use a dehydrator for 2O min 30°C and crush them into small pieces so you can use them to mix with copper sulphate.



n. Name Price Amount Source
01 Sodium hydroxide (NaOH) 4,10 € 1 kg Quimics Dalmau BCN
02 Distilled water 3-5 € 5 l Fablab BCN
03 Copper sulphate 7,60 € 1 kg Quimics Dalmau BCN
04 Baking soda 1,90 € 1 kg Quimics Dalmau BCN
05 Cream of tartar 12,20 € 1 kg Quimics Dalmau BCN
TOTAL - 29,80 € - -


  • NaOH composition - UNKNOWN

  • Urea composition - POSITIVE (purple)


  • ?



Timing Difficulty Safety
2-3 days Medium Low


  • gloves, measuring glass cup, rubber band, cutter / scissors


n. Name Price Amount Source
01 Cow intestines (stomach) 16,59 € 1 piece Cárnicas Teijeiro, Galícia
02 Distilled water 3-5 € 5 l Fablab BCN
TOTAL - 20 € - -



  • You have to select a proper glass jar for the dialysis regarding to the size of animal intestines. It will need enough space and water around your "dialysing" membrane.


Timing Difficulty Safety
6 h Low Low


  • gloves, measuring glass cup, rubber band, cutter / scissors


a. b.
Extraction Glycerol
90 % 10 %



n. Activity Price Timing Difficulty Safety
01 Wool composition x € 24 h Low Low
02 Chemical extraction x € 6 h Medium High
03 Filtration x € 1 h Low Low
04 Centrifuge x € 15 min Low Medium
05 Biuret testing x € 50 h Medium Low
06 Dialysis x € 72 h Medium Low
07 Preparation of hydrogel x € 6 h Low Low
TOTAL - 6 d 15 h 15 min - -

Last update: 2022-05-10