A method of constructing and screening a library of polynucleotide sequences of interest in filamentous fungal cells by use of an episomal replicating AMA1-based plasmid vector, thus achieving a high frequency of transformation and a stable and standard uniformly high level of gene expression. For example, users may interact with and control objects in a projection frame by moving andor gesturing with the handheld projector. The proportion of fetal nucleated cells present in the sample of peripheral blood can be increased forming a sample enriched in fetal nucleated cells prior to the detection step. Both loops have hard plastic buttons projecting therefrom which abut when the scissors are closed. Some of the derivatives may be useful as non-ionic surfactants. The magnet is periodically retractable to remove ferrous articles magnetically adhered thereto.