The PR2121-N-50BLK is the 5,000-reaction bulk pack of the Accuris qMAX Probe One-Step RT-qPCR Kit in the No ROX formulation — a probe-based one-step RNA-to-qPCR kit formulated for TaqMan®, Scorpions®, and molecular beacon probes. The optimized buffer includes a powerful RNase inhibitor and an extremely thermostable MMLV-derived reverse transcriptase for robust first-strand cDNA synthesis, paired with Accuris Hot Start Taq Polymerase using rapid antibody-mediated hot-start activation. The probe-based chemistry delivers higher specificity than SYBR Green-based detection (PR2120 sister kit) and supports multiplexing — though the dedicated Multiplex variants (PR2122 / PR2124) are the right pick for high-multiplex panels.
Key Specifications
| SKU | PR2121-N-50BLK |
| Type | One-Step RT-qPCR Kit — Probe-based detection chemistry |
| Reactions per pack | 5,000 reactions (bulk pack: 1 × 50 mL master mix + 4 × 1.25 mL ROX-free buffer per universe label hint) |
| Detection chemistry | TaqMan®, Scorpions®, and molecular beacon probe-based real-time qPCR |
| ROX formulation | No ROX — compatible with cyclers that don't require ROX normalization |
| Workflow | One-step (RNA template → qPCR result in one tube, one reaction setup) |
| Reverse transcriptase | Thermostable MMLV-derived |
| Polymerase | Accuris Hot Start Taq with antibody-mediated hot-start activation |
| RNase inhibitor | Included in optimized buffer |
| Cycler compatibility (No ROX) | Bio-Rad CFX, Roche LightCycler, and similar real-time cyclers that don't require ROX normalization |
| Multiplexing | Supported via probe chemistry; dedicated PR2122 / PR2124 Multiplex kits for high-multiplex panels |
| Pack size context | 50BLK = bulk-discount pack at as low as $0.50 per reaction (per Accuris brochure) |
| List price | $5,153 |
Probe vs SYBR Green Detection — qMAX Family Position
The qMAX RT-qPCR family ships in four detection chemistries:
| Kit family | Detection | When to pick |
| PR2120 qMAX Green | SYBR Green I dye | Cost-effective primary screening, gene-expression analysis with simple primer-based detection |
| PR2121 qMAX Probe (this kit's family) | TaqMan / probe-based | Specific target detection, low-noise quantification, low-level multiplex |
| PR2122 qMAX Multiplex | Multiplex probe | Multiple targets per reaction (multiplex panel) |
| PR2124 qMAX Multiplex 4X | Concentrated multiplex | High-multiplex panels, concentrated workflow |
Pick PR2121 (Probe) when probe-based detection is required for specificity (vs SYBR's dsDNA-binding non-specific detection) or for low-level multiplex (2-3 targets) where the dedicated Multiplex kits are overkill.
ROX Variant Family — N / L / H
The qMAX Probe kit ships in three ROX-formulation variants (same convention as PR2120 sister family):
| Suffix | ROX level | Compatible cyclers |
| N (this SKU) | No ROX | Bio-Rad CFX, Roche LightCycler, Eppendorf Mastercycler RealPlex |
| L | Low ROX | Applied Biosystems QuantStudio (newer), Stratagene Mx3000P/Mx3005P |
| H | High ROX | Applied Biosystems 7000/7300/7500/7900HT (older) |
Match the ROX variant to the lab's real-time cycler platform — using the wrong ROX formulation produces inaccurate normalization in cyclers that depend on ROX as a passive reference dye.
Workflow & Application
One-step RT-qPCR workflow. RNA template + kit master mix + gene-specific primers + probe (operator-supplied) in a single tube → reverse transcription + qPCR amplification + real-time detection in one thermal cycler run.
Probe-based detection. TaqMan probes (5' fluorophore + 3' quencher cleaved by Taq's 5' exonuclease activity), Scorpions probes (self-priming probe + reporter), or molecular beacon probes (hairpin probe with reporter) all supported. Probe-based chemistry delivers higher specificity than SYBR — only the target sequence generates fluorescence (no primer-dimer artifact signal).
Hot-start polymerase. Antibody-mediated hot-start activation prevents non-specific amplification during reaction setup at room temperature.
Cycler compatibility — No ROX. This formulation works with cyclers that don't use ROX as a passive reference dye for normalization.
Application Profile
Specific-target gene-expression quantification — when the workflow needs probe-based specificity beyond what SYBR Green provides (low-abundance targets, splice-variant discrimination, allele-specific quantification).
Pathogen detection workflows — clinical-research and surveillance labs running probe-based pathogen detection (viral RNA quantification with TaqMan probes for specific viral targets).
Low-level multiplex — 2-3 target multiplex panels where the PR2121 Probe kit covers the workflow without needing the dedicated PR2122 Multiplex kit.
Diagnostic-research-grade RT-qPCR — translational research workflows that require validated probe-based RT-qPCR chemistry at institutional volume.
Bulk-pack institutional procurement — labs running >5,000 probe-based RT-qPCR reactions per year benefit from the bulk-pack per-reaction discount.
Ordering & Configuration
Storage & handling. Per kit instructions — typical RT-qPCR master mix storage at −20 °C with limited freeze-thaw cycle tolerance.
Cycler compatibility verification. Critical at order: confirm the lab's real-time cycler platform requires the No ROX formulation. If the cycler requires Low ROX or High ROX, order the PR2121-L-50BLK or PR2121-H-50BLK variant instead.
Probe procurement separately. This kit supplies the master mix; probes (TaqMan, Scorpions, molecular beacon) are operator-supplied per the workflow's specific target.
Confirm at quote: real-time cycler platform and ROX requirement, expected workflow throughput, shipping conditions (cold-chain), and lead time.
Warranty: Per Accuris Life Science Reagents standard kit warranty terms — confirm at quote.
qMAX Probe One-Step RT-qPCR Kit family — pack-size variants for No ROX:
- PR2121-N-50BLK (this product) — 5,000 reactions, bulk pack
- PR2121-N-1000 — 1,000 reactions
- PR2121-N-500 — 500 reactions
- PR2121-N-100 — 100 reactions
- PR2121-N-S — sample size
Match the pack size to the lab's expected workflow throughput. For SYBR Green detection, see PR2120 sister kit; for high-multiplex panels, see PR2122 / PR2124.
