Patent ID: 7666308

Claim:
An improved method for optically analyzing microbiological specimens suspended in a fluid medium by magnetically labeling said specimens, which method comprises containing said magnetically-labeled specimens in a chamber having an optically-transparent viewing face having an interior surface, positioning said chamber into a magnetic field having a substantially uniform region of vertically-directed magnetic gradient and such that said chamber is located in said uniform region, collecting a uniformly-distributed layer of said magnetically-labeled specimens on the interior surface of said optically-transparent viewing face of said chamber, and conducting optical analysis of said magnetically-labeled specimens while maintaining said magnetically-labeled specimens collected on said interior surface of said optically-transparent viewing face of said chamber, and wherein said improvement comprises collecting said uniformly-distributed layer of said magnetically-labeled specimens within preformed V-grooves on said interior surface of said optically-transparent viewing face of said chamber.