Abstract: The enumeration and analysis of residual white blood cells in a sample of leukocyte-reduced blood products is conducted by forming a suspension of the leukocyte-reduced blood products with a sufficient amount of a lysing reagent. The lysing reagent comprises a buffer with a low molar concentration, and a non-ionic surfactant. The suspension of leukocyte-reduced blood products and the lysing reagent is incubated for a sufficient time at a temperature sufficient to selectively lyse the platelets and red blood cells without damaging the white blood cells. The white blood cells of the lysed blood products are then contacted with a suitable dye to stain the white blood cells and the number of stained white blood cells is measured. The lysing reagent is free of harsh organic solvents which can damage the plastic components of automated clinical analyzers.

Abstract: A siding panel with a cover sheet of hardboard fixed by an adhesive to an underlying backerboard of resin foam. Preferably the panels are installed with their longitudes extending horizontally. Each panel is secured to a wall frame by nails passing through spaced apart holes through the cover sheet adjacent its upper longitudinal edge and a locking structure adjacent the lower longitudinal edge of the panel. In the first course of panels the locking structure engages a starter strip nailed to the wall frame and in each succeeding course of panels engages the upper edge of an adjacent panel in the immediately preceding course. The locking structure is a tongue and preferably an adjacent recess in the lower longitudinal edge of the backerboard which when installed receives and interlocks with the upper nailed edge of the cover sheet of an immediately adjacent panel or a flange of a starter strip simulating an upper edge of a panel.