Preparing a slide of an identified arachnid specimen, such as a spider, involves several steps to ensure that the specimen is properly mounted and preserved for microscopic examination. Here’s a step-by-step guide for preparing a slide:
Materials Needed:
• Microscope slides
• Cover slips
• Forceps and fine needles
• Dissecting scissors or scalpel
• Ethanol (70-80%) or a preservative solution (e.g., glycerin)
• Clearing agents (e.g., lactic acid or clove oil)
• Mounting medium (e.g., Hoyer’s medium or Canada balsam)
• Labels for identification
• A microscope
Step-by-Step Procedure:
1. Specimen Collection and Preservation
o Collect the arachnid specimen using proper techniques (such as pitfall traps, hand collecting, or beating methods).
o Preserve the specimen immediately in ethanol (70-80%) to prevent decay and maintain its morphological features.
2. Cleaning the Specimen
o Before mounting, rinse the specimen in distilled water to remove any debris or excess preservative.
o Handle the specimen gently with forceps or fine needles to avoid damaging delicate structures like the legs or mouthparts.
3. Clearing the Specimen (Optional)
o To enhance the transparency of the specimen, place it in a clearing agent like lactic acid or clove oil for several hours or overnight.
o This step is particularly useful for examining internal structures and making fine details more visible under the microscope.
4. Mounting the Specimen on the Slide
o Place a drop of mounting medium (e.g., Hoyer’s medium or Canada balsam) in the center of a clean microscope slide.
o Carefully position the specimen in the medium using fine forceps or needles. Make sure the arachnid is placed in a way that allows important features to be clearly visible (e.g., legs spread out, dorsal or ventral side up).
5. Positioning the Cover Slip
o Gently lower a cover slip onto the specimen. Start from one edge and slowly lower the other side to avoid trapping air bubbles.
o Use forceps or a fine needle to position the cover slip if necessary, making sure it lies flat and even.
6. Sealing the Slide
o Once the cover slip is in place, seal the edges with a thin layer of clear nail polish or a sealing medium to prevent the slide from drying out and to protect it from contamination.
7. Labeling the Slide
o Label the slide with important information, including the specimen’s identification (e.g., Araneae family or species), collection date, location, and any relevant notes.
o Use a permanent marker or printed labels to ensure the information remains legible.
8. Drying and Curing
o Allow the slide to dry and cure for at least 24-48 hours (depending on the mounting medium used) before examining it under the microscope.
o Store the prepared slide in a horizontal position to prevent the medium from shifting.
9. Microscopic Examination
o Once the slide is properly prepared and dried, examine the specimen under a microscope.
o Adjust the microscope settings to highlight specific morphological features, such as chelicerae, pedipalps, spinnerets, or other structures that are important for identification.
Tips for Successful Slide Preparation:
• Handle with Care: Avoid damaging delicate structures while cleaning and positioning the specimen.
• Avoid Air Bubbles: Lower the cover slip slowly to minimize the risk of trapping air bubbles, which can obstruct the view under the microscope.
• Proper Storage: Store the slides in a cool, dry place to prevent deterioration over time.
This process will help ensure that the identified arachnid specimens are properly prepared and preserved on slides, allowing for detailed study and identification under a microscope.