G-361 / G-361-luc Orthotopic Mouse Model Service for Melanoma

The G-361 / G-361-luc orthotopic mouse model establishes a BRAF-mutant, melanin-producing human malignant melanoma within the skin of immunodeficient mice, where its documented tumorigenic and metastatic behavior in animal systems supports both localized efficacy testing and dissemination-oriented study designs. Alfa Cytology delivers this ATCC- and ECACC-curated human melanoma with authenticated banking, intradermal orthotopic or subcutaneous implantation configurations, melanin-production quality control across defined passage windows, and quantitative luciferase imaging in vivo, so your targeted agents, signal-pathway inhibitors, and combination strategies are evaluated on one of the most durable characterized human melanoma substrates available.

Overview of G-361 / G-361-luc Orthotopic Mouse Model for Melanoma

G-361 (ATCC CRL-1424; ECACC 88030401) is a human malignant melanoma line with epithelial morphology, isolated from the skin of a 31-year-old White male and deposited by P.T. Peebles, with a characterization record stretching back to 1978. Its curated attributes are unusually specific: the cells produce melanin for up to fifty population doublings — a finite pigment-production window that makes early-passage banking a genuine experimental requirement — they attach slowly in culture, and they carry a triploid karyotype with a modal chromosome number of 69. In a landmark profiling of twenty-one human melanoma lines, G-361 ranked among the tumorigenic and metastatic lines in animal models, a behavior that has carried it into decades of xenograft work. Molecularly, G-361 is classified as a BRAF-mutant, NRAS wild-type melanoma: it overexpresses the scaffolding adapter GAB2, which cooperates with MAPK pathway signaling in metastatic melanoma biology, and it responds to pathway-appropriate inhibition — colony formation and proliferation are suppressed by the MERTK inhibitor UNC2025, with enhanced effects when combined with BRAF-pathway agents such as vemurafenib.

Fig 1. Ex vivo bioluminescence validation showing linear luciferase signal from titrated G361 Gal3KD.Luc cells (2.5×10⁶–3.125×10⁵) in immunodeficient mice, followed by endpoint dissection revealing markedly more liver metastatic foci (arrows) in G361 Gal3KD mice than ScrCtrl, with corresponding lungs and brain gross images and quantified liver metastasis counts confirming that Galectin-3 knockdown promotes G361 metastatic dissemination. (Mohammed, Norhan BB, et al., 2024)

Placed orthotopically — intradermally, where cutaneous melanoma actually arises — or subcutaneously as the standard benchmarking configuration, G-361 forms measurable human melanoma xenografts in immunodeficient hosts, and its metastatic capability in animal systems opens designs that localized flank models cannot attempt. The G-361-luc derivative adds firefly luciferase for whole-body bioluminescence in vivo, enabling imaging-guided staging, metastasis-aware monitoring, and combination studies with quantified kinetics. Its curated heritage carries practical weight: ECACC documents its full STR profile, the melanin production window, and a hormone-response application history, while ATCC lists it at biosafety level 1. For programs that need a BRAF-mutant human melanoma with authentic pigment biology, a defined passage window for phenotypic integrity, and five decades of characterization behind every comparison, G-361 remains one of the most quietly dependable models in the melanoma literature.

Cell Line Information: G-361 / G-361-luc

G-361 grows in vitro as an adherent epithelial monolayer in McCoy's 5a medium with 2 mM glutamine and 10% fetal bovine serum, split 1:3 to 1:6 from sub-confluent cultures at 70–80% — with the caveat that the cells attach slowly and deserve gentle handling during plating and passaging. Melanin production is passage-limited: pigment is documented for up to fifty population doublings, so studies whose biology depends on pigmentation are best served by low-passage banks. The G-361-luc derivative adds firefly luciferase for quantitative imaging in vivo, with monoclonal selection of high-signal clones in vitro recommended for uniform bioluminescence.

Our Services

Characterized human melanoma lines reward operators who respect their documented quirks: G-361's pigment window closes with passage, its slow attachment punishes rough passaging, and its value as a metastatic model depends on low-passage integrity being protected throughout expansion. Alfa Cytology runs G-361 programs with passage-tracked banking that keeps pigmentation-dependent studies within the fifty-doubling window, gentle-handling SOPs matched to the slow-attachment phenotype, both intradermal and subcutaneous configurations, and imaging-aware endpoint panels — so the biology your study depends on is the biology that arrives at the endpoint.

Workflow of G-361 / G-361-luc Orthotopic Mouse Model Construction

G-361 model construction is operationally straightforward but passage-sensitive: pigment-dependent questions require early-passage banks, and the slow-attachment phenotype shapes every handling step. The workflow below covers construction from passage-tracked cell preparation through metastasis-aware endpoints.

1. Passage-Tracked Cell Expansion and Quality Control: G-361 or G-361-luc cells are expanded in vitro in McCoy's 5a + 2 mM glutamine + 10% FBS from low-passage banks, split 1:3–1:6 at 70–80% confluence with gentle handling given slow attachment; batches are confirmed mycoplasma-negative, STR-authenticated, and verified for melanin production, with monoclonal luciferase populations confirmed for tagged lines.
2. Host Selection and Acclimatization: BALB/c nude or NSG mice, typically 5–7 weeks of age, are acclimatized for approximately one week under SPF conditions and health-screened before assignment to study cohorts.
3. Inoculum Preparation: Cells are detached gently, washed in PBS, and resuspended at the working concentration; standard challenges are 2–5 × 10⁶ cells in ~100 µL for subcutaneous implantation or 25–50 µL for intradermal delivery, with passage number documented alongside every implantation record.
4. Subcutaneous or Intradermal Implantation: For the benchmark configuration, cells are implanted subcutaneously into the flank; for the orthotopic configuration, the same inoculum is injected intradermally into shaved dorsal skin using a fine needle, forming a small dermal bleb — both sites recorded for kinetics and downstream analysis.
5. Monitoring: Tumors are measured by caliper two to three times weekly, with visible pigmentation documented photographically; G-361-luc cohorts are imaged weekly by bioluminescence in vivo after D-luciferin administration, and body weight is recorded throughout.
6. Randomization and Treatment: Animals are randomized once tumors reach predefined volumes (commonly 100–200 mm³); test agents are dosed on study-defined schedules — BRAF-pathway, MERTK, or other targeted inhibitors, alone or in combination — with body weight and clinical condition monitored as tolerability readouts.
7. Survival Follow-Up: Animals are followed to standard tumor-burden euthanasia criteria with Kaplan–Meier analysis, and metastasis-oriented designs extend observation to organ-level assessment.
8. Endpoint Analysis and Reporting: At termination, tumors are excised, photographed for pigmentation, and weighed; lungs, lymph nodes, and liver are screened for metastatic spread consistent with the line's documented metastatic behavior; tissues are processed for H&E and melanoma-marker immunohistochemistry (S100, tyrosinase, or gp100), ex vivo bioluminescence maps signal distribution in luciferase studies, and tumor-growth, imaging, and pathology data are compiled into the final report.

Fig 2. G-361 / G-361-luc orthotopic mouse model construction workflow.

Case Study-G-361 / G-361-luc Orthotopic Mouse Model Development

G-361 xenografts are a durable presence in the human melanoma preclinical literature, and the platform has carried a broad range of Alfa Cytology client programs — BRAF-pathway and signal-transduction inhibitor evaluation, receptor-tyrosine-kinase targeting, melanogenesis and pigment-biology research, and metastasis-oriented designs exploiting the line's documented tumorigenic and metastatic behavior in animal models. Across these programs, readouts have combined caliper or bioluminescence kinetics in vivo, pigmentation documentation, and metastasis screening at necropsy. Anonymized case summaries and representative deliverable formats are available on request.

Why Choose Alfa Cytology?

G-361's five decades of characterization translate into operational requirements — and Alfa Cytology has built its human melanoma service around meeting them.

• A BRAF-mutant, NRAS wild-type human melanoma with curated ATCC and ECACC records behind every comparison.
• Authentic pigment biology with a documented fifty-population-doubling production window, protected through passage-tracked banking.
• Documented tumorigenic and metastatic behavior in animal models, supporting dissemination-oriented designs beyond flank benchmarking.
• Gentle-handling SOPs matched to the slow-attachment phenotype that rough passaging would quietly compromise.
• Flexible configurations spanning subcutaneous benchmarking and intradermal orthotopic implantation within one protocol.
• Pathway-aware endpoint panels: melanoma-marker immunohistochemistry (S100, tyrosinase, gp100) and pigmentation documentation.
• Monoclonal, high-signal luciferase banks with quantitative imaging in vivo for metastasis-aware monitoring.

Contact Us

If your program needs a thoroughly curated, BRAF-mutant human melanoma whose pigment biology and metastatic potential are documented rather than assumed, the G-361 / G-361-luc orthotopic model delivers — and Alfa Cytology protects its passage-sensitive biology at every step. Reach out to us to review implantation configurations, passage-window planning, and metastasis endpoint panels, and receive a customized study quotation today.

For research use only. Not intended for any clinical use.