Small particle contamination analysis requires consideration of secondary contamination of our sampie. Protection of such samples is very important. The procedure for sampling with freshly pulled lengths of clear 3M Magic™ tape is a favorite procedure among forensic microscopists. The tape must be immediately pressed onto a clean surface; usually, a clean microscope slide. There it is protected from further contamination.

Microscopical study and identification is usually possible utilizing the tape backing as a coverslip. Its thickness Is about 56 μm, one-third of the recommended 170 μm, but quite adequate for objectives 4-20X, If you feel persnickety, you can use two thicknesses of the tape, a second one over the sampling tape, This will give you optimum images for 4-40X objectives. Three thicknesses of tape, at 168 μm, is very close to the recommended thickness of 170 μm for any or all objectives.