Slingshot Biosciences
Slingshot is a specialist in creating exceptional flow cytometry controls.
Slingshot Biosciences produces a portfolio of synthetic cell mimics, polymer-based particles engineered to recapitulate the biophysical, optical, and biochemical properties of primary cells addressing well-documented limitations of biologically derived controls in flow cytometry, cell therapy QA/QC, and assay development.
Filter products
ScatterBridge™ — Cross-Instrument Scatter Standardization
ScatterBridge™ is a dedicated FSC/SSC standardization control designed to harmonize scatter parameters across flow cytometers from different manufacturers, a capability not achievable with biological controls, which behave inconsistently across distinct laser and detector configurations. It consists of nine distinct hydrogel populations forming a 3×3 grid on an FSC vs. SSC plot, spanning the full range of biologically relevant scatter coordinates.
Key applications:
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Standardize scatter results from one instrument to another across multi-site studies or core facilities
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Check scatter linearity and validate detector performance
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Track instrument performance over time as part of routine daily QC
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Recalibrate FSC/SSC settings following major instrument servicing or repair
Key advantages:
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Nine synthetic hydrogel populations cover a wide, biologically relevant FSC/SSC range in a single product
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Stable, non-biohazardous, and shelf-stable at ambient temperature — no cold chain required
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Lot-to-lot consistency governed by manufacturing tolerances rather than biological variation
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Directly complements FlowCytes® for daily QC, with both products using the same cell-mimic platform
| Feature | ScatterBridge™ | Biological Controls | Polystyrene Beads |
|---|---|---|---|
| Cross-instrument FSC/SSC normalization | ✅ Designed for this | ❌ Instrument-dependent behavior | ❌ Requires readjustment per cytometer |
| Scatter range coverage | ✅ 9 populations (3×3 grid) | ⚠️ Cell-type limited | ⚠️ Limited size range |
| Lot-to-lot consistency | ✅ Manufacturing-defined | ❌ Donor-dependent | ✅ Generally consistent |
| Shelf life | ✅ Multi-year, ambient temp | ❌ Short | ✅ Long |
| Biohazard risk | ✅ None | ❌ Yes | ✅ None |
| Daily QC / linearity testing | ✅ Yes | ❌ Impractical | ⚠️ Possible but scatter-limited |
| Post-service recalibration | ✅ Purpose-built | ❌ Not standardized |
❌ Not applicable |
ViaComp® — Viability Controls
ViaComp® replaces freshly heat-killed or freeze-thawed cells with chemically defined synthetic live and dead populations, delivered in a ready-to-use dropper bottle. It uniquely covers both DNA-intercalating dyes (7-AAD, DAPI, PI) and amine-reactive Live/Dead Fixable dyes in a single product, with a positive peak exceeding 10⁵ MFI and near-zero non-specific binding. ViaComp® Flex extends compatibility to non-standard reagents and complex multi-parameter panels.
Key advantages over heat-killed/freeze-thawed controls:
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Chemically defined live:dead ratio fixed at manufacture — no operator variability
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FSC/SSC matches lymphocytes — no gate adjustments needed when switching to real samples
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Multi-year shelf life; no culture, heat-killing, or cryopreservation required
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No biohazard risk; compatible with the full Slingshot platform (HyParComp™, SpectraComp®, FlowCytes®)
High Capacity
High Functional Group
Density
Multi-Point Covalent Attachment
High Specificity
HTS Compatible
TruCytes™ — Quantitative Antigen Controls
TruCytes™ are synthetic particles displaying certified antigen copy numbers, replacing variable cell lines like Raji (CD19) or Daudi (CD20) in quantitative flow cytometry and CAR-T potency assays. They eliminate passage-dependent antigen drift — a recognized GMP confound in ATMP potency testing and enable direct antibody binding capacity (ABC) measurements without knowing fluorophore-to-protein ratios.
Product lines:
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CD19 Quant — four discrete antigen density populations for quantitative ABC measurement
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Potency CD19 / CD20 Kits — CAR-T effector:target controls; CD20 kit shows ~2× lower off-target cytokine effects vs. tumor cell lines
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Single-biomarker controls — CD2, CD3, CD25, CD30, CD33, CD45, CD117, EGFR
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BCMA & lymphocyte subset mimics (2024 expansion) — for leukapheresis starting material QC and CAR product release testing
| Feature | TruCytes™ | Raji/Daudi Cell Lines |
|---|---|---|
| Antigen copy number | ✅ Certified, discrete | ❌ Undefined, variable |
| Passage-dependent drift | ✅ None | ❌ Well-documented GMP confound |
| Biohazard risk | ✅ None | ❌ BSL-2 required |
| Shelf life | ✅ Multi-year (lyophilized) | ❌ Continuous culture needed |
| GMP/regulatory compliance | ✅ Certified reference material | ❌ Not certified |
| Off-target cytokine effects | ✅ ~2× lower | ❌ Tumor background confounds signal |