The invention provides novel affinity labels for Ser proteases of formula: L-A-X\u2014NH\u2014CHCCH2Cl\u2003\u2003 wherein L, A, X, and R\u2032 have any of the values defined in the specification, or salts thereof, as well as compositions comprising such compounds or salts. The phyto-percolate is believed to contain an enzyme having proteolytic activity. The corresponding transformation matrix is decomposed into a plurality of individual transformation operation matrices and a discrete transformation operation value, from a corresponding individual transformation operation matrix, is generated for each transformation operation to be performed upon the rasterized data. The preferred body includes one or more ferrous compounds, and the preferred face includes tungsten carbide. A first isolation film may be formed on the sidewall of the first collector. In an embodiment, a mask for use in patterning an underlying layer comprises opaque regions and transparent regions arranged to define a line having an end, a slit extending laterally through the line a spaced distance from the end of the line, and a feature extending above or below the space adjacent to the end of the line.