Abstract: An assembly for monitoring ionising radiation which comprises coated on a base a binder layer containing a polychlorinated hydrocarbon and a color former.The assembly can be used to monitor levels of radiation of from 0.1 MRads to 10.0 MRads.

Abstract: A diagnostic strip which comprises a base having coated thereon a dried layer which has been formed by coating onto the base an aqueous solution which comprises from 0.5 to 2.0% by weight of agarose and from 0.5 to 3.0% by weight of non-cross linked polyacrylamide or polyvinyl alcohol or a mixture of these polymers, the dried layer being 0.1 to 100 .mu.m thick and comprising 10 to 50% by weight solids.

Abstract: A method of preparing a diagnostic strip coated with agarose which comprises preparing a roll of web material so that an aqueous silver halide emulsion can adhere thereto on one side thereof, but which does not have a gelatin or any other proteinaceous layer on the prepared side then coating on the prepared side of the web by a continuous web coating method a layer of an aqueous agarose solution at a temperature of at least 40.degree. C., drying the coated agarose layer to provide a dried layer thickness of from 0.1 to 100 .mu.m which is dry to touch, but which comprises 10 to 50% w/w solids and cutting the coated web into strips of the required size.