Lamination of Thermoplastic Sheets as a Means of Mounting Histological Material

Permanent preparations of squashes, whole mounts and stained sections can be made by lamination of thermoplastic sheets. Classical procedures of staining and dehydration for sectioned material were used although dehydration after staining was not required for root tip squashes. Arranging the specimen with the identification label between two pieces of clear Vinylite plastic, 15 mils thick, tightening the preparation in a Photo-Seal Kit electric press and laminating for 3 min gave a finished preparation without the use of glass slides and cover slips. For root tip squashes, the stained tip was placed with a drop of stain between two pieces of plastic, squashed and then laminated. This insured retention of all the tissue which is sometimes lost during mounting processes. Preparations of unstained whole mounts were similarly laminated, with an identification label added between the plastic sheets. Stained sections were placed between two sheets of plastic but the identification label was placed on top of the preparation and a third piece of plastic added. This prevented the label from absorbing excess stain and the increased thickness allowed the slide to be used in a mechanical stage. Well preserved slides 18 mo old indicate that the laminated plastic slide is quite durable. It saves time, reveals good cytological detail and avoids some of the laborious features of other methods. It is a technic that can be used in introductory microtechnic and in the preparation of slides for class use in histology.