biological effects such as receptor binding. Examples include the
CALUX reporter gene assay for dioxin-like compounds [16] and
yeast-based estrogen assays [17,18]. The cell culture and incubation
requirements may mean that screens are not much quicker
than instrumental methods. For example, minimum times for dioxins
analysis using GC/HRMS and by CALUX are both about 3 days
from sample receipt to result. However, screens offer much higher
analytical throughput as they are often in multi-well plate format
and utilise small quantities of material, facilitating parallel processing
of large numbers of samples. Many screens can provide
results that correlate reasonably well with confirmatory analytical
methods, but lack evidence of the robustness required in regulatory
compliance monitoring.