Methylcellulose has an extremely wide range of uses, of which several are described below.Scientifically Advanced CookeryMethylcellulose, as a gel, has the unique property of setting when hot and melting when cold. This technique is currently being developed at the University of Nottingham, in co-ordination with leading culinary alchemist Heston Blumenthal. Blumenthal’s wishes were to “make a warm ‘ice cream’ or ‘ice lolly’ on a stick, which the customer will have to eat before it cools down and melts.”.Thickener and emulsifierMethylcellulose is often added to hair shampoos, tooth pastes and liquid soaps, to generate their characteristic thick consistency. This it also done for foods, for example ice cream or whipped cream. Methylcellulose is also an important emulsifier, preventing the separation of two mixed liquids.The E number of methylcellulose as food additive is E461.Treatment of constipationWhen eaten, methylcellulose is not absorbed by the intestines but passes through the digestive tract undisturbed. It attracts large amounts of water into the colon, producing a softer and bulkier stool. It is used to treat constipation, diverticulosis, hemorrhoids and irritable bowel syndrome. It should be taken with sufficient amounts of fluid to prevent dehydration.Because it absorbs water and potentially toxic materials and increases viscosity, it can also be used to treat diarrhea.A well-known trade name of methylcellulose when used as a drug is Citrucel by GlaxoSmithKline, but generic versions are also widely available.LubricantMethylcellulose is used as a variable viscosity personal lubricant; it is the main ingredient in K-Y Jelly.Artificial tears and salivaSolutions containing methylcellulose or similar cellulose derivatives (see below) are used as substitute for tears or saliva if the natural production of these fluids is disturbed.Paper and textile sizingMethylcellulose is used as sizing in the production of papers and textiles. It protects the fibers from absorbing water or oil.Glue and binderMethylcellulose can be employed as a mild glue which can be washed away with water. This is used for example in the fixation of delicate pieces of art.Methylcellulose is the main ingredient in many wallpaper pastes.It is also used as a binder in pastel crayons.Methylcellulose is used in book conservation to loosen and clean off old glue from spines and bookboards.Construction materialsMethylcellulose finds a major application in construction materials. It is added to mortar dry mixes to improve the mortar’s properties such as water retention, viscosity, adhesion to surfaces etc.Cell culture/virologyMethylcellulose is also used in cell culture to study viral replication. Methylcellulose is dissolved in the same nutrient containing media that cells are normally grown in. A single layer of cells are grown on a flat surface, then infected with a virus for a short time. The strength of the viral sample used will determine how many cells get infected during this time. The thick methylcellulose media is then added on top of the cells in place of normal liquid media. As the viruses replicate in the infected cells they are able to spread between cells whose membrances touch each other, but are trapped when they enter the methylcellulose. Only cells closely neighboring an infected cell will become infected and die. This leaves small regions of dead cells called plaques in a larger background of living uninfected cells. The number of plaques formed is determined by the strength of the original sample.Special effectsThe slimy, gooey appearance of an appropriate preparation of methylcellulose with water, in addition to its non-toxic, non-allergenic, and edible properties, makes it popular for use in special effects for motion pictures and television wherever vile slimes must be simulated. In the film Ghostbusters, for example, the gooey substance that supernatural entities used to “slime” the Ghostbusters was mostly a thick water solution of methylcellulose.