What is the NCTC equivalent of ATCC 25922 (the CLSI M100 E. coli QC strain)?

NCTC 12241 is the CLSI M100 / EUCAST QC reference strain equivalent to ATCC 25922. Pro-Cult supplies it as a freeze-dried 10-disc vial. The full NCTC↔ATCC crosswalk is available on the crosswalk page, and the ATCC equivalent is listed on every Pro-Cult label where one exists.

Pro-Cult® First-Generation Quality Control Organisms — NCTC® and NCPF® Sourced

Q: How many passages can I make from a Pro-Cult working stock?

Up to four. The Pro-Cult Insert Issue 10 states a Pro-Cult disc is itself the first-generation subculture from the NCTC/NCPF master, and no more than four further passages from the Pro-Cult working stock should be made — keeping total passages from the master to the recommended maximum of five before genetic drift becomes a risk.

The only US-distributed QC organism line manufactured exclusively from NCTC® and NCPF® source strains under licence from the UKHSA Culture Collections — first-generation discs, UKAS-accredited COA per lot, NCTC↔ATCC equivalents where applicable.

Get a Quote Download Insert + Sample COA

ISO 13485:2016 Manufactured ISO 9001 Certified ISO/IEC 17025 — UKAS Lab #2496 UKHSA Culture Collections Licensed First-Generation, P1 ~80 Strains / 26 Genera 10-Disc Vials

Pro-Cult® is the only US-distributed quality control organism line manufactured exclusively from NCTC® and NCPF® source strains under licence from the UKHSA Culture Collections. Each freeze-dried disc is a guaranteed first-generation subculture of the master strain — not a multi-passage derivative. Every batch is tested in UKAS-accredited Lab #2496 with an online Certificate of Analysis available per lot. Pro-Cult gives clinical, pharmaceutical, food, water, and veterinary labs a documented second-source alternative to ATCC-derived QC products, with NCTC↔ATCC equivalents listed where applicable.

Pro-Cult® freeze-dried QC organism vials in retail blister pack — TCS Biosciences manufacture

Illustrative examples for layout; real testimonials from US adopters will replace these at launch.

Why First-Generation Source Matters

Manufactured From UKHSA Culture Collections Only

Pro-Cult discs are freeze-dried microbial preparations manufactured exclusively from NCTC® and NCPF® cultures under a manufacturing licence held with the PHE/UKHSA Culture Collections — the European peer authenticated source to ATCC.

Source: Pro-Cult Insert Issue 10 (Sept 2019), Quality section

A First-Generation Subculture From the Master — Every Batch

Each Pro-Cult disc is the first-generation subculture from the NCTC/NCPF master strain, leaving you the full four-passage working-stock budget recommended by CLSI and ASM convention.

Source: Pro-Cult Insert Issue 10, Limitations section

UKAS-Accredited Per-Lot Certificate of Analysis Online

Every batch is tested for identification and characterization attributes in UKAS-accredited Lab #2496. Pull the per-lot COA from the TCS Biosciences online portal by Code, Lot, Strain, or Strain Designation — no vendor email, no audit-day delay.

Source: Pro-Cult Insert Issue 10, Quality section; verifiable at ukas.com

Both NCTC and ATCC Equivalents on Every Label

Pro-Cult labels and COAs carry both the NCTC number and the ATCC equivalent where applicable, so your CLSI M100, EUCAST, and CAP IQCP SOPs need only an addendum line — not a rewrite.

Source: Pro-Cult Insert Issue 10, Quality section

A Defensible Second-Source QC Organism Program — Without Rewriting Your CLSI M100 SOPs

You own the QC plan, the CAP audit, and the answer when a Microbiologics back-order hits a M100 cycle. Pro-Cult® is the only US-distributed QC organism line manufactured exclusively from the UKHSA Culture Collections (NCTC®/NCPF®), with first-generation discs, UKAS-accredited per-lot COA, and NCTC↔ATCC equivalences listed where applicable. Adopt it as your primary or as your second source — your IQCP plan and your inspectors will both thank you.

Manufactured under TCS Biosciences' PHE/UKHSA Culture Collections licence, exclusively from NCTC® and NCPF® strains.
First-generation P1 from master — your lab keeps the full four-passage working-stock budget per CLSI / ASM convention.
CAP IQCP-ready under the 2024 Microbiology Checklist — first-generation traceability is a defensible IQCP risk-mitigation factor.

Request the Parallel-Run SOP and a Quote

Switching QC Organisms Doesn't Mean Retraining Your Bench — Pro-Cult® Labels Carry Both the NCTC and ATCC Numbers

You're the one who actually opens the vial, plates the disc, and signs the lot release. Pro-Cult is built for that bench reality: each freeze-dried disc softens in 10–15 minutes for direct plating or dissolves in 1–10 mL of broth, every label shows both the NCTC and ATCC numbers, and the per-lot COA is one click away on the TCS Biosciences UKAS-accredited portal. Switching takes an SOP addendum and a 30-day parallel run — not a QC plan rewrite.

Solid-media direct plating in 10–15 minutes — no broth pre-step required.
Liquid-media reconstitution in 1–10 mL of appropriate broth — match your existing inoculum SOP.
Per-batch COA online via the TCS Biosciences UKAS Lab #2496 portal — search by Code, Lot, Strain, or Strain Designation, with wildcard support.

Download the 30-Day Parallel-Run SOP

GPO-Priced, Supply-Continuity-Documented, and Approved Through Your Existing Vendor Onboarding

You don't need to switch formularies to add Pro-Cult®. We price-match your existing QC organism GPO tier on matched SKUs, ship from US fulfillment as UN3373 Cat. B refrigerated (no hazmat surcharge), and provide the ISO 13485:2016 and ISO 9001 manufacturer certificates, the ISO/IEC 17025 (UKAS Lab #2496) batch-testing accreditation, the NCTC/NCPF licence statement, and a supply-continuity SLA with the W-9 and credit application. Onboarding through your standard vendor process — no special procurement carve-out.

Pricing parity — Pro-Lab matches existing QC organism GPO tiers on equivalent SKUs.
US shipping, no hazmat surcharge — UN3373 Cat. B refrigerated, same logistics profile as Microbiologics.
Vendor-onboarding packet ready — ISO 13485 + ISO 9001 + ISO 14001 certs, ISO/IEC 17025 (UKAS Lab #2496) accreditation, NCTC/NCPF licence statement, supply-continuity SLA, sample COA.

Request a Per-SKU Quote

A Second-Source, NCTC/NCPF-Authenticated QC Organism Program for USP and Ph.Eur. Method Controls

Your USP <61>/<62> growth promotion, USP <71> sterility method suitability, and Ph.Eur. 2.6.12/2.6.13 controls require authenticated, traceable QC organisms — and your supply-continuity audit increasingly requires a documented second source. Pro-Cult® is manufactured exclusively from NCTC® and NCPF® source strains under UKHSA Culture Collections licence, batch-tested in UKAS-accredited Lab #2496, with online COA per lot. Pair it with your ATCC primary, or run it as the redundant authenticated source your QA system has been asking for.

NCTC/NCPF source authority — manufactured under PHE/UKHSA Culture Collections licence; NCTC numbers appear in many Ph.Eur. monographs.
First-generation P1 from master — reduces phenotype drift risk in growth-promotion and inhibitory test methods.
UKAS Lab #2496 batch testing with per-lot online COA — FDA Form 483-defensible documentation chain.

Compliance note: Pro-Cult is positioned as a QC organism material (lyophilized authenticated culture). It is not an ISO 17034 Certified Reference Material. Where your method explicitly requires CRM, source from an ISO 17034-accredited supplier. For routine growth-promotion, sterility-method-suitability, and inhibitory-substance testing where authenticated culture is acceptable, Pro-Cult is fit-for-purpose.

Request a Pharma QC Quote

Pro-Cult® Organism Catalog — NCTC ↔ ATCC Equivalents

The 20 most-frequently-ordered Pro-Cult strains for CLSI M100 / EUCAST AST QC, USP <61>/<62>/<71> growth promotion, and FDA BAM-method positives. The full ~80-strain catalog covers 26 genera across clinical, pharma, food, water, and veterinary QC. Each NCTC↔ATCC equivalence is documented on the per-lot COA.

Genus / Species	NCTC #	ATCC equiv.	Use case
Escherichia coli	NCTC 12241	ATCC 25922	CLSI M100 / EUCAST AST QC reference	Quote
Staphylococcus aureus	NCTC 12973	ATCC 29213	CLSI M100 / EUCAST AST QC reference	Quote
Pseudomonas aeruginosa	NCTC 12903	ATCC 27853	CLSI M100 / EUCAST AST QC reference	Quote
Enterococcus faecalis	NCTC 12697	ATCC 29212	CLSI M100 / EUCAST AST QC reference	Quote
Klebsiella pneumoniae	NCTC 13368	ATCC 700603	CLSI M100 ESBL QC reference	Quote
Escherichia coli	NCTC 10418	—	UK NHS routine media QC standard	Quote
Escherichia coli O157	NCTC 12900	ATCC 35150	FDA BAM Salmonella/STEC media QC	Quote
Salmonella enterica Typhimurium	NCTC 12023	ATCC 14028	FDA BAM XLD/Hektoen QC	Quote
Listeria monocytogenes	NCTC 11994	ATCC 19115	FDA BAM Listeria selective media QC	Quote
Candida albicans	NCPF 3179	ATCC 10231	USP <61>/<62> growth promotion	Quote
Saccharomyces cerevisiae	NCPF 3191	ATCC 9763	USP <61>/<62> growth promotion	Quote
Aspergillus brasiliensis	NCPF 2275	ATCC 16404	USP <61>/<62> growth promotion	Quote
Bacillus subtilis	NCTC 10400	ATCC 6633	USP <61>/<62> growth promotion	Quote
Clostridium sporogenes	NCTC 532	ATCC 19404	USP <71> sterility method suitability	Quote
Haemophilus influenzae	NCTC 11931	ATCC 49247	CLSI M45 fastidious AST QC	Quote
Neisseria gonorrhoeae	NCTC 12700	ATCC 49226	CLSI M45 / GC AST QC	Quote
Streptococcus pneumoniae	NCTC 12977	ATCC 49619	CLSI M45 / pneumococcal AST QC	Quote
Campylobacter jejuni	NCTC 11168	ATCC 700819	FDA BAM / CLSI M45	Quote
Bacteroides fragilis	NCTC 9343	ATCC 25285	CLSI M11 anaerobic AST QC	Quote
Vibrio parahaemolyticus	NCTC 10884	ATCC 17802	FDA BAM seafood / TCBS QC	Quote

Don't see your strain? The full Pro-Cult® catalog covers ~80 strains across 26 genera. Request a per-SKU quote →

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Pro-Cult® Line Specifications

Specification	Value	Source
Catalog number pattern	PLD## per organism (UK); US Pro-Lab Direct SKUs assigned at launch	pro-lab.co.uk product pages
Format	Freeze-dried disc	Pro-Cult Insert Issue 10
Pack size	10 discs per vial (standard line)	pro-lab.co.uk SKU pattern
Viable count guarantee	≥10⁶ organisms per disc at time of purchase; typical 10⁶–10⁹	pro-lab.co.uk product category page
Source strain bank	NCTC® and NCPF® (UKHSA Culture Collections) — exclusively	Insert Issue 10, Quality
Generation	First-generation subculture (P1) from NCTC/NCPF master	Insert Issue 10, Limitations
Recommended downstream passages	Up to 4 from the Pro-Cult working stock	Insert Issue 10, Limitations
Storage temperature	"At the temperature indicated on the label" — per SKU (most SKUs: 2–8 °C refrigerated)	Insert Issue 10, Precautions & Storage
Open-vial stability	9 months from first opening	pro-lab.co.uk product category page
Shelf life from manufacture	Per label expiry — do not use past expiry date	Insert Issue 10
Reconstitution — solid media	Place disc on medium, soften 10–15 min, spread, incubate	Insert Issue 10, Procedure
Reconstitution — liquid media	1–10 mL appropriate broth, shake gently, incubate	Insert Issue 10, Procedure
Rapid-use option	Dissolve, recover at 35–37 °C × 1 hr, then use immediately	Insert Issue 10, Procedure
Quality system (medical devices)	ISO 13485:2016 (TCS Biosciences)	TCS Biosciences attestation; Insert Issue 10
Quality management system	ISO 9001 certified (TCS Biosciences)	TCS Biosciences attestation
Environmental management	ISO 14001 certified (TCS Biosciences)	TCS Biosciences attestation
Batch testing accreditation	ISO/IEC 17025 — UKAS Lab #2496 (TCS Biosciences QC Laboratory) — accredited scope covers specified tests on Pro-Cult/Selectrol batches; verify schedule at ukas.com	TCS Biosciences attestation; Insert Issue 10, Quality
COA system	Online portal, per-lot, search by Code/Lot/Strain/Strain Designation	Insert Issue 10, On-line Certification System
Manufacturing licence	PHE/UKHSA Culture Collections × TCS Biosciences	Insert Issue 10, Quality
Distributor / brand owner	Pro-Lab Diagnostics	Insert Issue 10
Shipping classification (typical)	UN3373 Cat. B Biological Substance	SDS / packaging
Hazmat surcharge	None	UN3373 Cat. B has no hazmat surcharge
Amazon FBA eligible	No (UN3373 excluded by Amazon dangerous-goods policy)	Amazon DG policy

Frequently Asked Questions

Pro-Cult is sourced exclusively from NCTC® and NCPF® (UKHSA Culture Collections) under a manufacturing licence held by TCS Biosciences Ltd, while Microbiologics products are sourced from ATCC. Each Pro-Cult disc is a first-generation subculture from the master strain (P1); Microbiologics LYFO DISK is delivered within four passages of the ATCC seed (≤P4). Both ship refrigerated at 2–8 °C as UN3373 Cat. B.

NCTC 12241 is the CLSI M100 / EUCAST QC reference strain equivalent to ATCC 25922. Pro-Cult supplies it as a freeze-dried 10-disc vial. The ATCC equivalent is listed on every Pro-Cult label and per-lot COA where one exists.

Yes. Pro-Cult organisms include the CLSI M100 reference strains by NCTC equivalent — E. coli NCTC 12241 (≡ATCC 25922), S. aureus NCTC 12973 (≡ATCC 29213), P. aeruginosa NCTC 12903 (≡ATCC 27853), E. faecalis NCTC 12697 (≡ATCC 29212), K. pneumoniae NCTC 13368 (≡ATCC 700603) — and CLSI M100 footnotes accept equivalent reference strains. Document the equivalence in your SOP.

Yes. EUCAST QC reference strain tables explicitly list NCTC numbers alongside ATCC numbers for routine AST QC, making Pro-Cult a direct match for labs running EUCAST methodology.

Up to four. Per the Pro-Cult Insert Issue 10 (Limitations section), a Pro-Cult disc is itself the first-generation subculture from the NCTC/NCPF master, and no more than four further passages from the Pro-Cult working stock should be made — keeping total passages from the master to the recommended maximum of five before genetic drift becomes a risk.

Every batch is tested for identification and characterization attributes in UKAS-accredited Lab #2496. A per-batch Certificate of Analysis is available online via the TCS Biosciences COA portal — search by Code, Lot Number, Strain, or Strain Designation. UKAS accreditation is independently verifiable at www.ukas.com.

Pro-Cult ships refrigerated as UN3373 Category B Biological Substance (no hazmat surcharge). Store at the temperature indicated on each SKU's label (most strains: 2–8 °C). Allow the vial to reach room temperature before opening, replace the cap immediately after each disc removal, and do not use discs past the labeled expiry date.

Yes. We provide a 30-day parallel-run SOP template that you run alongside your current QC reagent against the same media and AST plates. Equivalent phenotype across the parallel run is the switch criterion. SOP addenda only need to add the NCTC↔ATCC equivalence line; tech retraining is typically under 30 minutes.

Two cases: (1) when your method explicitly requires an ISO 17034 Certified Reference Material — Pro-Cult is an authenticated culture under ISO 13485, not a CRM, so source from an ISO 17034-accredited supplier; (2) when a regulatory submission cites the origin-of-record ATCC strain by ATCC number — use the ATCC genuine culture for that filing. For routine clinical micro, food, water, and most pharma method QC, Pro-Cult is fit-for-purpose.

Quality, Regulatory & Safety Information

“Pro-Cult® discs are intended for use in microbiological laboratories for the control of test methods. Being 1st generation derivatives traceable to recognised culture collection strains, Pro-Cult® discs are acceptable in accredited laboratories for the production of working stock cultures.”

Source: Pro-Cult Insert Issue 10 (Sept 2019), English Intended Use, page 1.

Principle: Pro-Cult® discs are freeze-dried microbial preparations manufactured exclusively from NCTC® (National Collection of Type Cultures) and NCPF® (National Collection of Pathogenic Fungi) cultures. The viability of the organisms is stabilised by the unique formulation of the disc. Each disc is a first-generation subculture from the master culture; rehydration in a recommended diluent or on appropriate solid media yields a viable inoculum at a known starting concentration suitable for QC of culture media, biochemical identification, antimicrobial susceptibility testing, and molecular workflows.

Reconstitution Procedure

Solid media — direct plating: Place a Pro-Cult® disc on the appropriate solid medium using sterile forceps or a sterile 10 µL inoculating loop. Allow the disc to soften for 10–15 minutes (the plate may be placed in an incubator to accelerate). Spread the softened disc around the plate. Incubate under optimum conditions for the strain.

Liquid media: Place the disc in 1–10 mL of the appropriate broth. Avoiding aerosols, shake the broth gently to dissolve the disc. Incubate under optimum conditions.

Rapid use: Dissolve the disc in 1–10 mL of appropriate broth, allow the culture to recover by incubating at 35–37 °C for 1 hour, then use immediately.

Limitations

“Repeated subculture can cause the characteristics of a strain to change. A Pro-Cult® disc is a first generation subculture from a master culture sourced from Public Health England Culture Collections, and is designed to be used to obtain working stock cultures for use in testing. It is generally accepted that no more than five passages (successive subcultures) should be made from the master culture, in order to avoid genetic drift and mutant selection. Therefore, no more than four passages from the Pro-Cult® working stock culture should be made.”

Source: Pro-Cult Insert Issue 10, Limitations section.

Not for use on patient specimens; for laboratory QC only.
Not an ISO 17034 Certified Reference Material — where method requires CRM, source separately from an ISO 17034-accredited supplier.
Not a substitute for an ATCC genuine culture in regulatory submissions naming the ATCC strain by number.
Risk Group 2 organisms require BSL-2 containment per institutional biosafety policy.

Biosafety, Handling, & Disposal

Pro-Cult is a biological-only product (no hazardous chemical components, no GHS classification). Most clinical-relevant strains in the line are Risk Group 2 — BSL-2 containment is required.

PPE: Standard BSL-2 PPE — gloves, lab coat, eye protection during reconstitution. Reconstitute Risk Group 2 strains in a Class II Biological Safety Cabinet.
Storage: Store at the temperature indicated on each SKU label. Allow vial to reach room temperature before opening; replace cap immediately after each disc removal (moisture ingress causes loss of viability).
Disposal: Autoclave at 121 °C for ≥30 minutes, or chemical decontamination per institutional biosafety protocol. Decontaminated material → biohazard solid waste per local regulation.
Spillage: Per Insert Issue 10 — exposed discs, contaminated packaging, and broken glass should be placed in a suitable container and either incinerated or autoclaved at 121 °C × 30 minutes; contaminated surfaces must be disinfected with a suitable bactericidal solution.

Quality Documentation

“Pro-Cult® batches are tested for a range of identification and characterisation attributes in UKAS accredited testing laboratory number 2496. A test report (Certificate of Analysis) for each batch of Pro-Cult® can be accessed via the TCS Biosciences Ltd website. The reporting of the test results via the website forms part of the UKAS accreditation.”

Source: Pro-Cult Insert Issue 10, Quality section. Verify Lab #2496 at ukas.com.

Pro-Cult® First-Generation Quality Control Organisms — NCTC® and NCPF® Sourced

Why First-Generation Source Matters

Manufactured From UKHSA Culture Collections Only

A First-Generation Subculture From the Master — Every Batch

UKAS-Accredited Per-Lot Certificate of Analysis Online

Both NCTC and ATCC Equivalents on Every Label

A Defensible Second-Source QC Organism Program — Without Rewriting Your CLSI M100 SOPs

Switching QC Organisms Doesn't Mean Retraining Your Bench — Pro-Cult® Labels Carry Both the NCTC and ATCC Numbers

GPO-Priced, Supply-Continuity-Documented, and Approved Through Your Existing Vendor Onboarding

A Second-Source, NCTC/NCPF-Authenticated QC Organism Program for USP and Ph.Eur. Method Controls

Pro-Cult® Organism Catalog — NCTC ↔ ATCC Equivalents

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Pro-Cult® Line Specifications

Frequently Asked Questions

Quality, Regulatory & Safety Information

Reconstitution Procedure

Limitations

Biosafety, Handling, & Disposal

Quality Documentation

Order or Quote Pro-Cult® QC Organisms

Get a Quote

Order Now

Book a Call

Download Insert + Sample COA

Pro-Cult® First-Generation Quality Control Organisms — NCTC® and NCPF® Sourced

Why First-Generation Source Matters

Manufactured From UKHSA Culture Collections Only

A First-Generation Subculture From the Master — Every Batch

UKAS-Accredited Per-Lot Certificate of Analysis Online

Both NCTC and ATCC Equivalents on Every Label

A Defensible Second-Source QC Organism Program — Without Rewriting Your CLSI M100 SOPs

Switching QC Organisms Doesn't Mean Retraining Your Bench — Pro-Cult® Labels Carry Both the NCTC and ATCC Numbers

GPO-Priced, Supply-Continuity-Documented, and Approved Through Your Existing Vendor Onboarding

A Second-Source, NCTC/NCPF-Authenticated QC Organism Program for USP and Ph.Eur. Method Controls

Pro-Cult® Organism Catalog — NCTC ↔ ATCC Equivalents

People Also Purchased

McFarland Standards

Pro-Loops™ Inoculation Loops

TestOxidase™ PL.390

Pro-Cult® Line Specifications

Frequently Asked Questions

Quality, Regulatory & Safety Information

Reconstitution Procedure

Limitations

Biosafety, Handling, & Disposal

Quality Documentation

Order or Quote Pro-Cult® QC Organisms

Get a Quote

Order Now

Book a Call

Download Insert + Sample COA

The 2024 CAP Microbiology Checklist Expanded IQCP Eligibility — Does Your QC Plan Reflect It?