Question 1

Why is sterile tissue harvest important in laboratory animal research?

Accepted Answer

Sterile tissue harvest prevents contamination of cells and organs collected from research animals, which is essential for cell and tissue cultures, protein and RNA analysis, and metabolic profiling. Using harvested tissues for in vitro experiments reduces overall animal usage in research, supporting the replacement principle of the 3 R's framework for humane research practices.

Question 2

What equipment and preparation are needed before starting a sterile tissue harvest?

Accepted Answer

The procedure requires a laminar flow hood running for at least 15 minutes before use. Disinfect the hood with 70% alcohol and place wet paper towels inside. Arrange sterile instruments in order of use from left to right to maintain unidirectional workflow. The sterile technician must wear a sterile gown and two pairs of sterile surgical gloves covering the wrists to prevent skin cell contamination.

Question 3

How are abdominal organs like the liver and spleen removed during sterile harvest?

Accepted Answer

For the spleen, position the animal in right lateral recumbency and cut directly over the organ, gently retracting it while avoiding punctures. For the liver, place the animal in dorsal recumbency, reflect it away from the diaphragm, and carefully sever membranes and blood vessels. The liver is fragile and easily punctured, so handle it carefully to prevent excessive blood release that could compromise tissue quality.

Question 4

What is the proper technique for harvesting the heart and lungs together?

Accepted Answer

Place the animal in dorsal recumbency and open the thoracic cavity by cutting through the abdominal muscle and diaphragm. Puncture the diaphragm at the lateral rib cage and extend cuts to the sternum. Grasp the trachea with forceps and sever it with scissors, then lift and remove lung attachments from the spinal surface until the heart and lungs can be lifted free from the chest cavity.

Question 5

How is the brain harvested using aseptic technique?

Accepted Answer

Strip the skin from the body and over the skull, then saturate with alcohol and remove outer gloves. Make a cut along the midline from the cervical area to the nose. Using dedicated sterile scissors, cut through the spine at the skull base and along the midline through the foramen magnum. Lever the parietal bones away, disrupt nerve attachments with a spatula, and break olfactory bulb attachments with forceps before dropping the brain into sterile media.

Question 6

What research applications use sterile tissue harvest techniques?

Accepted Answer

Neural stem researchers extract tissue from mouse neonatal brains to study stem cell development and cancer progression in vitro. Metabolic profiling studies analyze tissue metabolites using nuclear magnetic resonance spectroscopy. Immunologists harvest lungs aseptically to measure bacterial load in infection models, collecting samples at multiple time points to track disease progression.

Question 7

What roles do sterile and non-sterile technicians play during tissue harvest?

Accepted Answer

Both technicians wear masks and bouffants. The non-sterile technician euthanizes the animal, places the carcass on paper towels, soaks it with 70% alcohol, and opens sterile instrument packages without touching inner surfaces. The sterile technician wears a sterile gown and two pairs of gloves, removes instruments aseptically, and performs the actual organ extraction to maintain sterility throughout the procedure.

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