Rat FSTL1 (Follistatin Like Protein 1) ELISA Kit

What it means: Target is the analyte this ELISA kit is designed to measure. The target shown here is FSTL1.

How to interpret here: Treat FSTL1 as the “what you will quantify.” Because the species is Rat, the antibodies/standard are optimized for that organism. The listed sample types (Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples) tell you which matrices are expected to behave well with this target. Plan your dilutions so readings fall within the detection range (78.125-5000pg/ml). If you expect low abundance, compare your expected baseline to the sensitivity (46.875pg/ml). Choose this when the species/matrix match your study and you can keep samples within the kit’s working range; consider another kit if you need a different species validation, matrix validation, or lower detection limit.

In practice, the target defines the biology you can read out (pathway activity, disease models, treatment response) and determines what controls and validation steps you’ll need.

Why it matters for buying:

• Correct biomarker match: Confirms you’re measuring the intended protein/marker (closely related proteins or isoforms may behave differently).
• Species alignment: A species-matched kit (here Rat) reduces under-recovery from sequence differences.
• Format expectations: The assay type (Sandwich ELISA, Double Antibody) influences specificity, curve behavior, and tolerance to complex samples.
• Matrix fit: Intended matrices include Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples; unlisted matrices often require extra validation.

How it impacts your workflow:

• Dilution series first: Run serial dilutions to land in the linear part of the curve and avoid saturation or below-range noise.
• Controls: Include blank, standards, and (when possible) a known-positive matrix control; replicate low-level samples.
• Matrix validation: Use spike-recovery and dilution linearity (parallelism) before committing to a full cohort.

What to watch out for:

• Family members/isoforms: If specificity is critical, confirm datasheet cross-reactivity notes and consider an orthogonal method.
• Sample handling: Keep samples cold, minimize freeze–thaw cycles, and use recommended diluents to protect analyte stability.
• Near-limit calls: Close to 46.875pg/ml, small background shifts can change “detectable vs not”—tight technique matters.

What it means: Species indicates which organism the kit is validated/optimized to detect. The species shown here is Rat.

How to interpret here: Use Rat as a primary compatibility gate. This kit is intended to measure FSTL1 in Rat samples. Combine species with the sample-type guidance (Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples) to choose the right matrix and controls. Choose this when your study organism matches; validate carefully if you must use another species (spike recovery + parallelism) because sequence differences can reduce binding.

Species matching matters because even modest sequence differences can change antibody binding and distort quantification (weak signal, curve compression, or false negatives).

Why it matters for buying:

• Risk reduction: A mismatched species is a common reason ELISAs fail or under-recover.
• Comparability: Avoid comparing absolute concentrations across species unless you validated equivalent recovery in each species.
• Format interaction: In a Sandwich ELISA, Double Antibody assay, species mismatch can hurt both capture and detection steps.

How it impacts your workflow:

• Matrix-matched controls: Use matrix controls and keep diluent consistent.
• Cross-species pilot: If using another species, test spike recovery and dilution linearity before scaling up.
• Interpretation discipline: Keep matrix and species consistent across groups to reduce confounding.

What to watch out for:

• Serum vs plasma differences: Anticoagulants (EDTA/heparin) can shift background; keep matrix consistent within a study.
• Low-level targets: Species/matrix mismatch can push low signals below detectability—plan replicates and careful washing.

What it means: Sample Type(s) lists the matrices this kit is intended/commonly used for. The sample types shown are Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples.

How to interpret here: Treat Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples as your best clue for “where this kit behaves as expected.” Pair it with the species (Rat) to pick matrix- and species-matched controls. For complex matrices, plan dilutions so results land in 78.125-5000pg/ml. Choose this if your samples match these matrices (or you can validate a new matrix); consider another kit if you need validated performance in a different matrix with minimal development work.

Matrix choice strongly affects ELISA performance because background proteins, salts, lipids, and anticoagulants can change recovery and raise non-specific signal.

Why it matters for buying:

• Compatibility check: If your matrix isn’t listed, you may need extra validation (or select a kit validated for that matrix).
• Cost of failure: Matrix interference can force repeat runs; validated matrices save time and sample.
• Low-level detection: Near 46.875pg/ml, matrix background becomes a key limiter—validated matrices matter more.

How it impacts your workflow:

• Prep/clarify: Centrifuge to remove debris; consistent lysis/homogenization improves repeatability.
• Dilution series: Start with serial dilutions to find the linear region and reduce matrix effects.
• Validation checklist: Run spike recovery (spike standard into matrix) and parallelism (dilution linearity) before processing a full cohort.

What to watch out for:

• Hemolysis/lipemia: Can increase background; clarify and consider additional dilution.
• Protease activity: Some targets degrade; keep cold and use inhibitors where appropriate.

What it means: Assay Type describes how the ELISA generates signal and how the standard curve should be interpreted. The assay type shown is Sandwich ELISA, Double Antibody.

How to interpret here: Use Sandwich ELISA, Double Antibody to anticipate signal behavior and workflow strictness. With matrices like Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples, consistent prep and washing are key to control background. Pair with species Rat for best quantitative reliability. Also note the assay time (4 hours) for throughput planning. Choose this if the format matches your analyte and interpretation needs; consider another format if you need a validated competitive design or different curve behavior.

Assay format drives specificity, dynamic range, and how robust the assay is to matrix interference.

Why it matters for buying:

• Interpretation safety: Some formats have inverse curves (competitive)—knowing the type prevents mis-reading results.
• Fit for analyte: Format choice depends on analyte size/epitope availability and expected abundance.

How it impacts your workflow:

• Washing and timing: Follow wash counts/soak times and keep incubations consistent to reduce CV.
• Stay on the curve: Use a dilution series so sample readings fall within the curve (avoid saturation and baseline noise).
• Batch consistency: Run replicates, seal plates, and avoid edge effects.

What to watch out for:

• Matrix interference: Lipemic/hemolyzed samples can raise background—clarify and consider additional dilution.
• Very high concentration: Extremely high analyte can push assays into non-linear regions; dilution is your friend.

What it means: Sensitivity is the lowest concentration the assay can reliably distinguish from background under recommended conditions. The sensitivity shown here is 46.875pg/ml.

How to interpret here: Use 46.875pg/ml as a feasibility check for detecting the target at baseline. This kit measures FSTL1, and you’ll get the most reliable quantification when results fall within 78.125-5000pg/ml. In matrices like Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples, background can reduce practical sensitivity—pilot testing is recommended. Choose this if expected concentrations are comfortably above the sensitivity; consider a more sensitive kit if your baseline is near the limit or your matrix is challenging.

Sensitivity is related to, but not identical to, practical detection in every matrix. Real samples can raise background and effectively worsen the limit.

Why it matters for buying:

• Low-abundance feasibility: Helps you judge whether the kit can see expected baseline levels.
• Risk/time planning: Near-limit work often requires extra validation, replicates, and careful technique—factor into timelines and sample needs.

How it impacts your workflow:

• Pilot near expected range: Run dilution series to see where your samples land on the curve.
• Background control: Consistent washing, clean pipetting, and avoiding plate drying help preserve low-level detection.
• QC validation: Use spike recovery and parallelism, especially for serum/plasma and lysates.

What to watch out for:

• Hemolysis/lipemia: Can raise background and hide low signals.
• Inconsistent timing: Small incubation differences matter more at low concentrations.

What it means: Detection Range is the concentration interval where the assay is intended to quantify reliably. The detection range shown here is 78.125-5000pg/ml.

How to interpret here: Use 78.125-5000pg/ml to plan sample dilution and avoid re-runs. Sensitivity (46.875pg/ml) tells you how low you can reasonably detect, while the range tells you where quantification is reliable. In matrices like Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples, dilution helps reduce matrix effects and keep readings in-range. Choose this if your expected concentrations can be brought into this range with reasonable dilutions; consider a different range if your samples are consistently far above or below this window.

Staying within the working range improves accuracy and reduces the chance of saturation (too high) or unstable readings (too low).

Why it matters for buying:

• Quantitative reliability: Results are most dependable when OD values fall within the stated range.
• Dilution strategy: Guides how much to dilute (or concentrate) samples before running.
• Reduced repeats: Matching expected levels to range lowers the risk of repeat testing due to out-of-range data.

How it impacts your workflow:

• Pre-test: Run a small pilot or dilution series to bracket expected concentrations.
• Re-dilute when needed: If samples saturate, dilute further; if below curve, consider less dilution or a more sensitive kit.
• Keep conditions consistent: Use consistent diluent and timing to preserve curve shape.

What to watch out for:

• Non-linear edges: The lowest and highest points of the curve are often less stable; aim for mid-curve when possible.
• Matrix shifts: Different matrices can shift apparent concentrations—validate with spike recovery/parallelism.

What it means: Assay Time is the approximate hands-on + incubation time needed to complete the assay workflow under recommended conditions. The assay time shown here is 4 hours.

How to interpret here: Use 4 hours to plan throughput and workflow scheduling. With matrices like Serum, Plasma, Cell Culture Supernatant, cell or tissue lysate, Other liquid samples, allocate time for sample prep/clarification and consistent incubation timing. In a Sandwich ELISA, Double Antibody ELISA, timing consistency is key to keep the standard curve stable run-to-run. Choose this if the runtime fits your lab schedule and sample stability window; consider alternatives if you need faster turnaround or have many plates to process in parallel.

Assay time is not just convenience—timing affects reproducibility. Consistent incubations and washes help control background and improve inter-plate comparability.

Why it matters for buying:

• Throughput planning: Determines how many plates you can run per day and staffing needs.
• Sample stability: Some analytes degrade; longer workflows may require colder handling and careful batching.
• Reproducibility: Tight timing control reduces variability between plates or operators.

How it impacts your workflow:

• Batch strategy: If running many samples, stagger plate starts so wash/incubation timing stays consistent.
• Equipment readiness: Plan for plate washer (or manual wash), timer discipline, and consistent temperature conditions.
• Documentation: Record start/stop times for each step to troubleshoot drift across runs.

What to watch out for:

• Rushing washes: Short washes increase background; follow the recommended wash steps.
• Plate drying: Plates drying between steps can elevate background—keep workflow continuous.
• Operator-to-operator variation: Standardize timing and mixing to reduce variability.