A diagnostic enzyme request for quotation (RFQ) should describe enough technical and commercial information for suppliers to propose a relevant material, sample, documentation package, and production plan. A request that contains only an enzyme name and quantity often produces quotations that cannot be compared because the suppliers assume different sources, activity methods, formulations, or quality requirements.
A strong RFQ does not need to disclose confidential assay details. It should communicate the enzyme identity, intended functional context, required specifications, evaluation plan, supply expectations, and documentation needs with clear distinctions between mandatory requirements and preferences.
State whether the request is for feasibility testing, routine supply, scale-up, second-source qualification, custom expression, engineering, or replacement of an existing enzyme. This context helps the supplier determine whether an off-the-shelf material, modified formulation, custom production process, or development project is appropriate.
Provide the accepted enzyme name, common abbreviation, EC number if available, target sequence or accession when relevant, and required source or species. If a specific isoform, domain, mutation, tag, oligomeric state, or post-translational modification is needed, state it explicitly.
An EC number identifies a reaction rather than a unique protein product. It should not be used as the only identifier. If the RFQ is based on a current material, include the reference product, supplier, catalog number, and lot information when disclosure is permitted.
Suppliers can make better recommendations when they understand the enzyme's role. State whether it directly converts an analyte, supports a coupled reaction, acts as a reporter, removes an interferent, prepares a sample, or processes nucleic acids.
| Information | Examples |
|---|---|
| Assay format | Clinical chemistry, ELISA, CLIA, biosensor, lateral flow, PCR, RT-qPCR, LAMP, NGS |
| Sample matrix | Serum, plasma, whole blood, urine, saliva, swab eluate, extracted DNA or RNA |
| Operating conditions | Working pH, temperature, reaction time, ionic strength, instrument format |
| Key components | Substrate, cofactor, coupled enzyme, surfactant, preservative, inhibitor |
| Current problem | Low signal, high background, instability, inhibition, poor recovery, lot variation |
If exact formulation is confidential, provide ranges, representative conditions, or the specific performance challenge. Suppliers do not always need the full assay composition to assess technical feasibility.
Activity requirements are a common source of RFQ ambiguity. Specify the unit definition and measurement method, including substrate, pH, temperature, cofactors, reaction time, and detection. If acceptance will be based on your internal method, state that supplier samples will be tested internally.
Do not compare U/mg claims from different methods without alignment. If the supplier may use an alternate method, request the full procedure and a bridging plan. State whether the important measure is U/mL, U/mg, activity per vial, concentration-normalized assay response, or another functional result.
Define the purity method as well as the numerical requirement. SDS-PAGE, SEC, ion-exchange, reversed-phase chromatography, and other methods measure different aspects. A broad “greater than 95% purity” requirement is incomplete without a method.
Identify impurities or unwanted activities that could affect the assay. Examples include protease, nuclease, catalase, phosphatase, oxidase, reductase, residual host-cell protein, DNA, endotoxin, affinity ligand, or bioburden. Requirements should be risk-based; not every test is relevant to every enzyme.
A formulation requirement should be connected to its purpose. For example, glycerol-free material may be needed for drying, but simply removing glycerol without adding a compatible stabilization strategy can reduce shelf-life.
Describe intended storage, transport, freeze-thaw, in-use, and post-reconstitution conditions. Distinguish required existing evidence from future study expectations. If a target shelf-life is requested, clarify whether real-time data already exist, accelerated prediction is acceptable during development, or the supplier is expected to conduct a formal program.
| Commercial Item | Information to Provide |
|---|---|
| Evaluation sample | Amount, number of lots, formulation, requested delivery date |
| Initial order | Total mass or activity, fill configuration, number of containers |
| Annual forecast | Expected range, order frequency, growth assumptions |
| Batch size | Minimum and preferred production lot; reservation or campaign needs |
| Lead time | Routine, first-production, custom-development, and safety-stock expectations |
Enzyme quantity should include the basis: mass, activity, volume, or number of tests. If demand is uncertain, provide a range rather than an unsupported exact forecast.
Request only documentation that has a defined use. A large document list can slow sourcing without improving the decision if the materials are not reviewed or applicable.
Explain how samples will be evaluated and which results determine progression. The plan may include supplier CoA review, internal activity testing, formulation compatibility, matrix studies, assay performance, and short-term stress testing. If multiple suppliers are being compared, use a common method and standardized handling.
State whether acceptance of an evaluation sample qualifies only that lot or supports future supply. Routine lots may still require specifications, bridging, and change control.
Ask how a lot is defined, which tests are performed on every lot, how trends are monitored, and whether retained samples are available. Identify changes that require notification, such as sequence, host, source, manufacturing site, scale, process, purification resin, formulation, packaging, or analytical method.
For a critical raw material, discuss notification period, comparability support, last-buy options, and business continuity. These expectations are easier to establish before qualification than after routine supply begins.
Mark each item as required, preferred, optional, or to be developed. A supplier may have a technically suitable alternative that cannot be identified if every request is written as an absolute requirement. For example, a specific host may be less important than activity, impurity, and supply goals.
| Section | Minimum Content |
|---|---|
| Project | Purpose, stage, timeline, confidentiality |
| Identity | Name, EC number, sequence/source, isoform or tag |
| Use | Assay role, format, matrix, working conditions |
| Specifications | Activity method, purity, impurities, formulation, stability |
| Supply | Sample, quantity, batch size, forecast, fills, lead time |
| Quality | CoA, methods, traceability, change notification |
| Evaluation | Tests, acceptance criteria, number of lots, decision timing |
Create a comparison matrix before quotations arrive. Separate technical fit, documentation, development scope, commercial terms, and supply risk. Normalize units and quantities so that price per milligram is not compared with price per activity unit without conversion and method review.
| Evaluation Area | Questions |
|---|---|
| Technical fit | Does identity, activity method, purity, formulation, and stability address the intended use? |
| Evidence | Are values lot-specific, typical, preliminary, or guaranteed by specification? |
| Development scope | Which tasks, rounds, samples, methods, reports, and acceptance points are included? |
| Supply | What are batch size, lead time, capacity, safety stock, and change-notification terms? |
| Commercial | What are unit basis, minimum order, packaging, testing, shipping, and future-scale pricing? |
For custom expression or engineering, define deliverables by phase. A feasibility phase may include construct design, small-scale expression, purification, and activity screening. Later phases may cover optimization, scale-up, formulation, analytical characterization, and technology transfer. Specify decision gates and ownership of materials, constructs, methods, and data.
Timelines should identify dependencies, including receipt of customer reagents, assay transfer, sequence approval, and sample feedback. A low initial quotation may exclude characterization, repeat work, or scale-up, so scope alignment is more important than headline price.
Share enough information to support a technically relevant proposal while protecting confidential details. A confidentiality agreement may be appropriate before disclosing sequences, proprietary substrates, formulas, or performance limitations. If disclosure is restricted, provide representative pH, temperature, matrix, inhibitors, and performance targets.
