Cloud-Clone details rat model workflow for rheumatoid arthritis research

Cloud-Clone Corp. outlined a standardized adjuvant-induced arthritis rat model for studying rheumatoid arthritis and screening anti-inflammatory drug candidates. The workflow covers induction, scoring, histology and biomarker testing, with the company positioning the platform as a reproducible preclinical tool for autoimmune research.

Why it matters: - Rheumatoid arthritis is a chronic autoimmune disease that damages joints, cartilage and bone. - Human studies are limited by ethics and patient-to-patient variation. - A reproducible rat model gives researchers a controlled way to study disease mechanisms and test candidate drugs before clinical work.

What happened: - Cloud-Clone Corp. published a standardized workflow for an adjuvant-induced arthritis rat model. - The model is designed for rheumatoid-arthritis mechanistic research and anti-inflammatory drug screening. - The company described the platform as a complete technical overview covering model construction, evaluation endpoints and sample-testing workflows. - The release was dated Aug. 25, 2026.

The details: - The model uses SPF-grade male SD rats weighing 180 g to 220 g. - Study groups include a control group, a model group, a positive-drug control group and a test-compound treatment group. - The experimental window runs 4 to 6 weeks. - Researchers induce arthritis by injecting 0.1 mL complete Freund’s adjuvant intradermally into the right hind paw under anesthesia. - Control animals receive 0.1 mL of 0.01 mol/L glacial acetic acid subcutaneously in the right hind paw to rule out sensitization from CFA solvents. - Body weight is tracked on day 0, 7, 14, 21 and 28. - Spleens and thymuses are collected before euthanasia to calculate organ index. - Paw thickness is measured with an electronic vernier caliper at marked sites on day 0 and every 7 days through day 28. - Arthritis index scoring rates the three non-injected limbs from 0 to 4 based on visible inflammation and swelling. - Score 0 indicates no erythema or swelling. - Score 1 indicates erythema with mild swelling limited to the mid-paw or ankle joint. - Score 2 indicates erythema and mild swelling extending from the ankle across the mid-paw. - Score 3 indicates erythema and mild swelling spreading from the ankle to the digital joints. - Score 4 indicates erythema with severe swelling covering ankles, paws and digits. - After euthanasia, ankle joints are fixed, decalcified, embedded, sectioned and stained with H-E for histology. - Normal joints show intact structure, smooth cartilage and no inflammatory-cell infiltration. - Model-group joints show joint destruction, neutrophil infiltration, synovial hyperplasia, fibrous-tissue proliferation and cartilage-bone damage. - Blood is collected from the vena cava after 3% pentobarbital sodium anesthesia. - Serum is isolated after a 30-minute clotting period and centrifugation at 4000 rpm for 30 minutes at 4 °C. - Serum is stored at minus 80 °C for downstream analysis. - TNF-α and IL-1β are measured with ELISA kits. - The release says the model supports assessment of gross phenotype, immune-organ parameters, histopathology and circulating inflammatory markers. - Cloud-Clone says it operates a standardized SPF-grade animal-experiment platform and offers contract-research services for inflammatory and autoimmune disease models, drug administration, biomarker detection and pathological analysis. - The company also says it uses robust modeling protocols, end-to-end quality control and matched ELISA reagents to support reproducible datasets.

Between the lines: - The release is as much a service announcement as a methods summary. - Cloud-Clone is positioning itself as a preclinical research partner, not just a reagent supplier. - The emphasis on standardized inputs, timed measurements and multiple readouts suggests a focus on reproducibility, which is a major issue in animal-model research.

What's next: - Researchers can use the workflow as a template for rheumatoid-arthritis studies and drug screening. - Cloud-Clone says its platform can support ongoing animal-model generation, intervention studies and biomarker testing for immunology research. - The company directs readers to more information and lists social channels on LinkedIn, Instagram, TikTok and X.