How can I make a container for rat inhalations? - briefly
Use a sealed glass or acrylic chamber equipped with inlet and outlet ports, a HEPA filter, and a calibrated aerosol generator, ensuring all joints are airtight and pressure is monitored. Clean the apparatus before each session and dispose of contaminated materials according to biosafety protocols.
How can I make a container for rat inhalations? - in detail
To build a chamber suitable for delivering aerosolized substances to laboratory rats, follow these precise steps.
Select a transparent, non‑reactive body material such as borosilicate glass, polycarbonate, or stainless steel. The container should accommodate one to three animals comfortably, allowing free movement while preventing escape. Internal dimensions of roughly 30 cm × 20 cm × 20 cm provide sufficient space for adult rats.
Create airtight seals at all joints. Use silicone O‑rings or PTFE gaskets on lid flanges and port connections. A screw‑type lid with a silicone gasket ensures repeatable closure without compromising sterility.
Install inlet and outlet ports. The inlet must accept tubing from an aerosol generator; equip it with a stainless‑steel L‑connector and a miniature flow meter. The outlet should include a HEPA filter to capture excess aerosol and a vent line with a controllable vacuum pump to maintain a stable negative pressure. Position both ports opposite each other to promote uniform airflow.
Integrate a calibrated aerosol generator. A Collison nebulizer or a jet‑mill system can produce particles in the 1–5 µm range, appropriate for pulmonary deposition in rodents. Connect the generator to the inlet port using chemically resistant tubing (e.g., PTFE). Verify that the generator’s airflow rate matches the chamber’s volume to achieve the desired exposure concentration, typically 0.5–2 L/min per animal.
Add monitoring devices. Install a temperature probe and a hygrometer inside the chamber to keep environmental conditions within physiological limits (20–24 °C, 40–60 % RH). Include an optical particle counter or a photometer at the outlet to confirm aerosol concentration in real time.
Provide a removable floor grate. Use stainless‑steel mesh that supports the animal while allowing aerosol to pass through. The grate should be easy to disassemble for cleaning and decontamination between sessions.
Implement a cleaning protocol. After each use, flush the interior with 70 % ethanol, rinse with sterile water, and dry with filtered air. Autoclave removable components (grate, gaskets, tubing) when material compatibility permits.
Validate the system. Conduct a test run with a harmless tracer aerosol (e.g., sodium fluorescein) and collect deposition samples on filter pads placed in the animal’s breathing zone. Analyze concentration and particle size distribution to confirm that the chamber meets experimental specifications.
Document all dimensions, material specifications, flow rates, and validation results. Maintain records for reproducibility and regulatory compliance.