Effects of Field Operations on Laboratory Test Plans

The information obtained from the field, or from the agency delivering the sample, can have a direct bearing on decisions pertaining to the preliminary assessment, analytical test plan, and the type of laboratory capabilities required in the analyses (Figure 11.1). If a laboratory manager determines from the field information that the analyses requested are outside the laboratory's capability, he or she should immediately inform the submitting agency to consider alternatives. Otherwise, poorly performed analyses or limited capabilities of an analytical laboratory may be difficult to defend in court, thereby compromising the case and wasting valuable sample, time, and resources.

In cases where there is limited sample and limited analytical capability in the field, decisions must be made to determine the extent of testing to be performed on site before the sample is shipped to an analytical laboratory. In lieu of definitive assays at the site of an incident, there are proposals for first-responders to use simple assay kits to determine whether a powder or other material is a biological substance.6-9 These proposed kits include tests for protein (found in most biological agents), pH (to determine whether the sample is in the biological range pH 6 to 8), and solubility (salts and sugars will produce a clear solution in aqueous fluids, whereas bacteria and spores will produce a turbid suspension). The downside of this approach is that valuable sample for subsequent laboratory analysis may be consumed and forensic evidence may be destroyed before the FBI and other investigational agencies have the opportunity to secure the situation. In other words, forensic testing may be hampered by contamination, alteration, or depletion of materials.1,2

0 0

Post a comment