English: Amphivasal vascular bundles of cross section of leaf petiole of eagle fern (Pteridium aquilinum) under microscope

Native, aqueous or temporary slides, as they are also called, are slides that last for a certain period of time and ordinary water is used for their preparation. They are easy and fast to make, do not require additional reagents and they are quite practical for observing certain structures under a microscope. The procedure for their preparation begins with the preparation of the object and cover glass which should be wiped nicely. Two drops of water are placed on the object glass, one central large and one peripheral smaller drop of water. The cross section is made with the help of an ordinary blade, with which the object (leaf petiole of eagle fern) is held in the right hand, and the blade in the left. At the beginning it is always necessary to catch up the object at the place where the intersection will be made. The section is made by holding the object at eye level and moving the blade from outside to inside and with careful movements left and right, without pressing. The purpose of this procedure is to make a section as thin as possible through which light from the microscope will pass easily. The cross section prepared in this way is taken with the help of tweezers and placed in the central drop of water on the object glass. A cover glass is placed on it, which is lowered next to the peripheral drop of water and at an angle of 45 ° it moves towards the middle of the object glass until the moment when the two drops of water merge, during which it is lowered. This procedure needs to be performed precisely because otherwise air bubbles will form which will count during microscopy. In this way the native microscopic slide is prepared and it is ready for microscopy.

Prepared and performed by Sara Cvetanoska, Institute of Biology, FNSM, Ss. Cyril and Methodius University, Skopje, Macedonia.