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Wistar / SD rats

Jiangsu Aniphe BioLab operates a high‑standard SPF‑grade laboratory animal facility, maintaining large‑scale Wistar and SD rat colonies. It can reliably supply rats of multiple ages and body weights, along with standardized disease‑modeling services. Supported by a robust supply chain and an agile response system, the company ensures that experimental rats are readily available on demand, significantly shortening research and drug‑development timelines and providing robust animal resources for metabolic, neurological, and toxicological studies.

Strain Introduction

Wistar rats and Sprague‑Dawley (SD) rats are the two most widely used outbred, inbred rat strains in biomedical research worldwide, spanning nearly all areas of biology—from basic physiology and toxicological safety assessment to the development of disease models. Both are albino strains, characterized by a docile temperament, high reproductive capacity, rapid growth, and a moderate life span. They also benefit from extensive background data and broad regulatory acceptance, making them the gold-standard, universally applicable models for preclinical studies.

Product Advantages

Excellent genetic traits

The population exhibits low genetic variation and excellent experimental reproducibility; inbreeding depression is avoided, resulting in superior animal vigor and reproductive performance.

Baseline data is sufficient.

Accumulate extensive historical control data on physiology, pathology, and toxicology to minimize experimental variable confounding.

The experiment is easy to perform.

The albino phenotype facilitates external observation, and the animals exhibit a gentle temperament, making it easy to administer drugs, collect blood, and perform surgical procedures. They also demonstrate strong environmental adaptability and are straightforward to rear.

Compliance-Driven Toxicology R&D

Complies with domestic and international regulatory guidelines, including those of the OECD, ICH, and NMPA, and is suitable for pharmacological and safety evaluations of drugs.

Modeling has wide-ranging applications.

It can both conduct routine drug safety studies and rapidly generate metabolic, cardiovascular, and neurological disease models through induced animal modeling.

 

Data parameters

Strain Name

Wistar rat; Sprague-Dawley rat (SD rat)

Strain type

Outbred Closed Colony

Fur color

Albino

Genetic background

First established at the Wistar Institute in 1906, it is now the most widely distributed closed colony rat worldwide; in 1925, Sprague and Dawley developed it through selective breeding based on the Wistar strain, and it has since become the preferred rat model for toxicology research globally.

Microbial Grade

SPF grade

Available by week of age

3–8 weeks

Application areas

Wistar rat
● Nutrition and Metabolism Research: Diet-induced obesity (DIO), prediabetes, and lipid metabolism disorders.
● Neuroethology: Elevated plus-maze, Morris water maze, and forced swim test can serve as screening models for depression- or anxiety-like behaviors.
● Cardiovascular Basic Research: Common background conditions for surgical models such as pressure-overload–induced cardiac hypertrophy and renovascular hypertension (Goldblatt model).
● Immunity and Inflammation: Adjuvant-induced arthritis (AIA), contact dermatitis, and other immune-related diseases.
● Reproductive and Developmental Toxicology: Teratogenicity sensitivity period studies, two-generation reproduction studies, and the like are advantageous because they involve stable reproductive cycles and low spontaneous mutation rates.
SD rat
● Drug Safety Evaluation (GLP Toxicology): The rodent model of choice for acute toxicity, chronic toxicity, reproductive toxicity, and carcinogenicity studies, and it continues to enjoy the highest level of trust from regulatory authorities worldwide.
● Pharmacokinetics (PK) / Toxicokinetics (TK): Greater body weight facilitates repeated blood sampling and yields a wealth of baseline metabolic data.
● Surgical model: Unilateral ureteral obstruction (UUO)-induced renal fibrosis, partial hepatectomy, carotid artery balloon injury, and so on.
● Pregnancy and Fetal Programming: Due to their high litter size and uniform pup size, they are frequently employed in studies examining the long-term effects of maternal stress and nutritional interventions on offspring.
● Aging Research: The lifespan is approximately 2.5 to 3 years and is commonly used for longitudinal studies of natural aging and age‑related diseases.

Breeding Techniques and Precautions

Strictly control inbreeding systems to mitigate genetic diversity.

Environmental and Caging Management

Standardized control of temperature, humidity, and lighting; frequent replacement of adequate bedding to reduce ammonia irritation; provision of enrichment materials to mitigate stereotypic behaviors and prevent light‑induced ocular damage in albino rats.

 

Strictly control environmental stimuli to reduce experimental stress.

Feed and Water Management

Standard maintenance chow was provided ad libitum, while a high-fat diet was used to induce obesity, with food intake recorded. Acidified and sterilized drinking water was administered, and the water lines were cleaned regularly to prevent heavy metal poisoning.

 

Standardize breeding management to improve the survival rate of pups.

Key Points of Breeding Operations

Adapt the mating age to achieve a 1-male–2-female ratio, which enhances conception rates; prior to parturition, separate male mice into individual cages to reduce maternal stress; within 48 hours of birth, minimize direct handling and implement gradual odor acclimatization within the cage.

 

Monitor age-related spontaneous lesions and eliminate experimental confounding.

Quarantine and Experimental Adaptation

Newly acquired rats should undergo a 7–14-day quarantine period, with continuous monitoring for SPF‑specific core pathogens. Albino rats are highly stress‑sensitive; after transport, they should be allowed to rest for 5–7 days before experimental procedures to prevent hormonal fluctuations from confounding the results.

 

Literature support

Scientific publications based on this model, as cited by Aniphe customers, are supported for SCI‑indexed publication. (Original paper link)
1. Exp Mol Med 2024 Oct;56(10):2184-2201;
Article Title: Cbx4 SUMOylates BRD4 to regulate the expression of inflammatory cytokines in post-traumatic osteoarthritis.
2.J Nutr Biochem 2024 Apr;126:109578；
Document Title: Alginate oligosaccharide alleviates vascular aging by upregulating glutathione peroxidase 7.
3.Am J Hypertens 2025 May 17；
Title: OGT-mediated O-GlcNAc of PINK1 promotes the progression of obesity-related hypertension via regulating mitophagy.
4.Biol Trace Elem Res 2024 Sep 27;
Document Title: Iron Level in Pregnant Rats is Associated with Caries Susceptibility in Offsprings.
5. Naunyn Schmiedebergs Arch Pharmacol 2024 May;397(5):3301-3312;
Title: Bakuchiol regulates TLR4/MyD88/NF-κB and Keap1/Nrf2/HO-1 pathways to protect against LPS-induced acute lung injury in vitro and in vivo.

Frequently Asked Questions

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Q1: Which strain should I choose—Wistar or SD?

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A: For GLP‑compliant toxicology and safety assessments, when substantial historical control data are required, or when a larger body weight is desired to facilitate multiple blood collections, Sprague‑Dawley rats are the preferred choice.

When the focus is on metabolic phenotyping, neurobehavioral studies, or chronic disease models such as diabetes or obesity, Wistar rats are often more suitable, as they exhibit slightly less body‑weight variability, respond more consistently to high‑fat diets, and certain Wistar substrains (e.g., Wistar Kyoto) can be used as models of hypertension or depression.

General principle: For safety assessments, select the SD strain; for studies on physiological mechanisms and metabolic diseases, select the Wistar strain.

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Q2: How to distinguish between Wistar and SD rats:

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A: On the surface, it’s still quite difficult to tell them apart. However, you can use body shape and skin elasticity as helpful clues.

▪ Wistar rats have a stocky, compact body with a broad head; males, in particular, have slightly longer ears than those of other strains. Their tails are shorter than their body length. In contrast, SD rats are slender and elongated, with a narrow, elongated head and a tail nearly as long as the body.

▪ Skin elasticity. SD rats have relatively tight skin, whereas Wistar rats exhibit looser skin. Wistar rats are characterized by high reproductive capacity, large litter sizes, stable estrous cycles, early sexual maturity, a docile temperament, strong disease resistance, and a low spontaneous tumor incidence. SD rats are commonly used in nutritional studies; they are highly responsive to sex‑hormone stimulation, grow rapidly, produce smaller litters, and display robust resistance to respiratory diseases. These distinctions are relative; the choice of strain should ultimately be guided by the specific objectives and requirements of the experiment.

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Q3: Is it normal for SD rats to grow faster than Wistar rats?

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A: This is normal. One of the breeding objectives for SD rats is rapid growth; under comparable conditions, their body weight at the same age is typically 10–20% higher than that of Wistar rats. This facilitates the rapid attainment of body weights used to extrapolate human-equivalent doses in short-term toxicology studies. However, in long-term experiments, the spontaneous tumor incidence may be slightly higher than in Wistar rats, a factor that should be accounted for in the experimental design.

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