Agarose-based Cell Block Technique for Preparation of Cell Blocks from the Residues of Liquid-based Cytology Samples

초록

Background: When the cell blocks are prepared using a simple sedimentation method, a considerable loss of diagnostic material is inevitable especially when the quantity of cells in sample is very low. We illustrate a modified method for preparartion of agarose cell blocks that enables to achieve adequate celluarity yield within the minimal viewing areas of sections of the cell blocks that are prepared from the residues of liquid-based cytology samples remaining after routine smear preparations of fine needle aspirations and effusions. Methods: The residues of LBC samples remaining after routine smear preparations were fixed in formalin and centrifuged. Then. the cell pellets were re-suspended with minimal volumes of 2-3% agarose solution. The suspensions were solidified at 4℃ to make agarose cell buttons, and then they were embedded in 2-3% agarose to make agarose gel disks. Then, the resulting disks were processed and embedded in paraffin in the same way as tissue samples. Sections cut from the cell blocks were stained for H&E staining and immunostaining. Results: By using minimal volumes of agarose solution as intermediate media to resuspend the cell pellets, the residues of SurePath samples were easily and entirely transferred into small agarose cell buttons. The solidified agarose cell buttons measured 3-4mm in size and were ground glass opaque, each with a well formed half-round convex surface. When they were re-embedded in the agarose gel, the resulting agarose gel disks were well formed, each with a cell button incased at the bottom. They were easy to manipulate for procedures for processing and paraffin embedding: