1. Make up a washing powder, adding 1-2
g of protease for every 100
g of enzyme-free
powder.
2. Use a 1% solution of the mixture.
3. Add strips of photographic film about 4 mm wide to the washing powder solution.
4. Incubate in a water bath
at 50-60oC for 10-20
minutes, or until the film has cleared.
Gentle agitation may be needed.
5. Record the time taken to completely clear the photographic film.
6. Remember to carry out suitable
controls using enzyme-free washing
powder solution alone.
Safety
The enzymes used here are identical to those found in
washing powders. They are
encapsulated in a low melting-point
wax and are therefore safe to handle and unlikely to
form airborne dust. Unnecessary
contact with the dissolved enzyme should be avoided.
Wash splashes with plenty of water. Spills of enzyme
solution should be wiped up promptly.