How to prepare lice? - briefly
To prepare lice for analysis, collect them with a fine‑toothed comb and preserve the specimens in 70 % ethanol. After fixation, mount the insects on microscope slides using an appropriate mounting medium for detailed observation.
How to prepare lice? - in detail
Preparing lice specimens for scientific examination requires systematic steps to preserve morphology and enable accurate observation.
First, collect live insects from the host using fine-toothed combs or adhesive tape. Transfer each specimen into a labeled container with a small amount of humidified cotton to maintain viability until processing.
Second, immobilize the insects. Place them on a chilled surface (2–4 °C) for several minutes, or expose them briefly to carbon dioxide. Immobilization prevents damage during subsequent handling.
Third, fix the specimens. Immerse the lice in a fixative solution such as 70 % ethanol or a formalin–ethanol mixture (4 % formaldehyde, 70 % ethanol) for 12–24 hours at room temperature. Fixation stabilizes tissue structures and halts enzymatic decay.
Fourth, dehydrate the samples. Transfer the fixed insects through a graded ethanol series (70 %, 80 %, 95 %, 100 %) with 15‑minute intervals for each concentration. Complete dehydration prepares the specimens for clearing or embedding.
Fifth, clear the tissue. Replace ethanol with a clearing agent (e.g., xylene or clove oil) for 10‑15 minutes. Clearing renders the cuticle more transparent, facilitating microscopic assessment.
Sixth, embed the cleared lice in a suitable medium. Options include paraffin wax for histological sectioning or resin for whole‑mount preparation. Follow the embedding protocol recommended for the chosen medium, ensuring proper orientation of the specimen.
Seventh, section or mount. For paraffin-embedded samples, cut 5‑10 µm sections with a microtome, place sections on charged slides, and dry. For resin-embedded whole mounts, trim the block to expose the region of interest and polish the surface.
Eighth, stain the sections or mounts. Common stains include hematoxylin‑eosin for general morphology, or specific dyes such as Masson's trichrome for connective tissue. Apply stain according to standard timing, then rinse and dehydrate through ascending ethanol concentrations.
Ninth, mount the stained sections with a permanent mounting medium (e.g., Canada balsam) and cover with a glass coverslip. Seal edges to prevent drying.
Finally, examine the prepared specimens under appropriate magnification using light or electron microscopy. Document observations with photomicrographs, noting structural details such as head capsule, thoracic sclerites, and abdominal segmentation.
Adhering to this workflow ensures high‑quality lice preparations suitable for taxonomic identification, morphological research, or educational demonstration.