Research Variables and Quality Control

What are research variables?

Factors that can affect research results

What is the goal with non-experimental variables?

Keep them to a minimum

What are intrinsic factors?

Factors inherent to the animal

What are examples of intrinsic factors?

Genotype, age, sex, and immune status

What are extrinsic factors?

Factors external to the animal

What are examples of extrinsic factors?

Environment, diet, infectious agents, caging, temperature, humidity, noise, and chemicals

Why is genotype important in research?

Genetic differences affect biological responses

What can different mouse strains have?

Different anesthesia responses, immune responses, virus resistance, and inherited diseases

Why are inbred animals used?

To collect reproducible and comparable data

What are outbred animals used for?

To maintain genetic variability

What is genetic divergence?

Changes or differences in genetic makeup that must be monitored

How can strain purity be checked?

Skin grafting, serology, microcytotoxic assays, mixed lymphocyte reactions, biochemical markers, and DNA techniques

What are biochemical markers?

Enzyme or protein variants unique to strains

What DNA techniques can detect small genetic changes?

Southern blotting and PCR

What sample sources can be used for DNA testing?

Tail or ear tissue, saliva, fecal pellets, and hair follicles

How can age affect research?

It affects respiratory rate, blood pressure, oxygen demand, metabolism, kidney function, and thermoregulation

Why are neonates important in research variables?

They may be more sensitive to carcinogenic compounds

How can older animals affect research?

They may have decreased cardiovascular, hepatic, and kidney function

How can sex affect research?

Male and female hormones can produce different responses

How can immune status affect research?

Immune-deficient animals react differently to microbes and carcinogenic agents

What is the macroenvironment?

The room or surrounding area around the animal

What is the microenvironment?

The cage or immediate housing area in direct contact with the animal

What physical extrinsic factors affect animals?

Cage design, temperature, humidity, ventilation, lighting, and noise

What does The Guide set guidelines for?

The macroenvironment

Why is temperature control important?

Extreme temperatures can cause serious physiologic effects

What temperature exposure can be dangerous to unadapted animals?

Below 45°F or above 85°F

What can extreme temperatures affect in breeding animals?

Sterility or reduced milk production

Why is floor space important?

It supports health, social needs, and normal behavior

How long should animals acclimate before experiments?

48 hours

Why is wire flooring not recommended?

It can negatively affect animal health and welfare

What chemical extrinsic factors can affect research?

Insecticides, cleaning agents, contaminants in food, water, or bedding, and pharmaceuticals

What is toxicity based on?

Dose and disposition of the chemical

What is a teratogen?

A substance that can cause developmental defects

Why is food a major chemical variable?

It can contain contaminants and nutrient levels affect physiology

How can protein and fat levels affect animals?

Breeding, body weight, longevity, and mortality

What should lab animal food be?

Palatable, noncontaminated, and nutritionally adequate

What should lab animal water be?

Potable and uncontaminated

Why can water cause experimental variation?

It may contain heavy metals, pesticides, or volatile organics

How can pharmaceutical agents affect experiments?

They can create confounding effects like cardiovascular or respiratory depression

What are microbes?

Pathogenic organisms that can cause clinical disease

How can microbes be transmitted?

Food, bedding, water, fomites, caretakers, and contaminated biologic materials

Why should human-animal contact be limited?

To reduce disease transmission

What are adventitious agents?

Agents that occur accidentally, spontaneously, or from an external source

What is vertical transmission?

Transfer of a pathogen from parent to offspring

What is horizontal transmission?

Transfer from infected to naive animals by air, direct contact, fomites, or vectors

What is the key to stopping chain of infection?

Prevention

What should be done with incoming rodent containers?

Inspect them, disinfect them, quarantine animals, and monitor health status

What PPE can limit contact with animals?

Gloves, gowns, and masks

How should food and bedding be stored?

Off the floor and from reputable vendors

How can food and bedding be sterilized if needed?

Autoclaving or gamma irradiation

What is quality control?

A program that safeguards animal and human health and ensures reliable research

What does a quality control program include?

Health surveillance, testing, sentinel animals, and proper protocols

What health surveillance methods are used?

Microscopic exam, parasitology, serology, PCR, and microbial culturing

What is serology mainly used for?

Rodent health monitoring

What are sentinel animals?

Animals used to monitor colony health

How are sentinel animals exposed to pathogens?

Soiled bedding transfer or exposure to exhaust air

Why should QC protocols be clear?

Test results should be meaningful

How should agents be prioritized in monitoring?

By prevalence and potential animal or human health impact

How is disease prevention supported?

Proper management of data and personnel