This disclosure provides, among other things, a method for processing a membrane comprising rolling circle amplification (RCA) products. In some embodiments, this method may comprise: (a) obtaining a porous capillary membrane that comprises fluorescently labeled RCA products that are in or on the membrane; (b) depositing a curable polymer onto the membrane; and (c) curing the curable polymer to encapsulate the RCA products in a solid. In some embodiments, the curable polymer may be a silicone and may be transparent in its solid form. A kit for performing the method and a composition made by the method are also provided.