Published specifications & documentation

Most suppliers describe their quality system and then ask you to enquire before showing you any numbers. We would rather show you the numbers. Everything on this page is taken from the specification sheets our manufacturing partner publishes for the catalogue items we source — expression system, purity method, concentration, buffer composition and storage, item by item.

sST2 (IL1RL1) — antigen and matched antibodies

The sST2 line is supplied as a matched set: a recombinant antigen and three antibodies raised against it. That shared immunogen is what makes a sandwich format practical, because capture and detection reagents were generated against the same material rather than assembled from different sources.

Recombinant sST2 antigen

Manufacturer catalogue L4C01501 · example lot shown: L170401

Product	Recombinant human ST2 antigen
Molecular weight	40 kDa (as stated by the manufacturer)
Source / expression system	E. coli
Purification	Affinity purified
Concentration	1.4 mg/ml
Buffer	10 mM PBS, pH 7.4, 1 mM EDTA, 0.1% SKL, 0.2% NaN₃
Preservative	0.2% NaN₃
Stated applications	Standard in immunoassay; immunogen for antisera production; tracer for iodination
Storage & shelf life	-20 °C for 3 years; avoid multiple freeze/thaw cycles
Manufacturer's use statement	For research use only. Not for use in diagnostic procedures.

Expressed in E. coli and affinity purified. Note the stated applicability as an immunogen for antisera production — sST2 is used in VHH and conventional antibody development as well as in assays, and an antigen intended for immunisation has different requirements from one intended as a calibrator.

Anti-sST2 antibody — suggested capture

Manufacturer catalogue L3C01201 · example lot shown: L180601

Product	Mouse monoclonal anti-sST2 (suggested capture)
Host / isotype	Mouse, IgG
Source	Ascites
Immunogen	Purified human sST2 antigen
Format	Affinity purified, liquid, Protein A chromatography
Purity	>90% (SDS-PAGE)
Concentration	4.38 mg/ml (OD280 nm)
Buffer	0.01 M PB, 150 mM NaCl, pH 7.4
Preservative	None
Stated applications	ELISA and Western blot; working titre to be determined by the user
Storage	-20 °C

Mouse monoclonal, Protein A purified, supplied without preservative. For a capture reagent the absence of preservative matters when the antibody is to be conjugated or coated directly onto a solid phase.

Anti-sST2 antibody — labelling / detection

Manufacturer catalogue L3C01202 · example lot shown: L180601

Product	Mouse monoclonal anti-sST2 (labelling / detection)
Host / isotype	Mouse, IgG
Source	Ascites
Immunogen	Purified human sST2 antigen
Format	Affinity purified, liquid, Protein A chromatography
Purity	>90% (SDS-PAGE)
Concentration	5.8 mg/ml (OD280 nm)
Buffer	0.01 M PB, 150 mM NaCl, pH 7.4
Preservative	None
Stated applications	ELISA and Western blot; working titre to be determined by the user
Storage	-20 °C

Same host and immunogen as the capture antibody, supplied unconjugated so that the labelling chemistry and label-to-protein ratio remain under your control.

Anti-sST2 polyclonal (rabbit)

Manufacturer catalogue L3C01203 · example lot shown: L170901

Product	Rabbit polyclonal anti-sST2
Host / isotype	Rabbit, IgG
Source	Ascites
Immunogen	Purified human sST2 antigen
Format	Affinity purified, liquid, Protein A chromatography
Purity	>90% (SDS-PAGE)
Concentration	9 mg/ml (OD280 nm)
Buffer	0.01 M PB, 150 mM NaCl, pH 7.4
Preservative	None
Stated applications	ELISA and Western blot; working titre to be determined by the user
Storage	-20 °C

A second host species against the same antigen, which gives an alternative capture option without introducing a new immunogen into the system.

cTnI — recombinant and native antigen, with a stated antibody pair

Cardiac troponin I is available in two antigen forms from the same manufacturer, and the choice between them is a decision about your documentation obligations as much as about biochemistry.

Recombinant cTnI antigen

Manufacturer catalogue L4C00102 · example lot shown: L180901

Product	Recombinant human cardiac troponin I (cTnI)
Molecular weight	Approximately 30 kDa (as stated by the manufacturer)
Source / expression system	Expressed in E. coli
Purity	>90% (SDS-PAGE)
Concentration	1.1 mg/ml
Buffer	10 mM PBS, pH 7.4, 0.01% SKL
Preservative	None
Stated applications	Standard in immunoassay; immunogen for antisera production; tracer for iodination
Storage & shelf life	-20 °C for 3 years; avoid multiple freeze/thaw cycles
Manufacturer's use statement	For research use only. Not for use in diagnostic procedures.

E. coli expressed, so the material carries no donor-screening obligations — which is normally what you want in a calibrator. The trade-off is that an E. coli-expressed preparation is not glycosylated and does not reproduce the phosphorylation state of circulating troponin.

Purified native cTnI (human heart tissue)

Manufacturer catalogue L4C00101 · example lot shown: L180501

Product	Purified native human cardiac troponin I
Source	Human heart tissue
Immunological activity	Confirmed by reaction with a monoclonal antibody specific for the cardiac troponin I isoform in immunoblotting
Format	Purified, liquid
Concentration	4.4 mg/ml
Buffer	20 mM Tris, pH 7.5, with 5 mM EDTA and 15 mM mercaptoethanol
Preservative	None
Stated applications	Standard in immunoassay
Storage & shelf life	-20 °C for 3 years; avoid multiple freeze/thaw cycles
Donor screening	The tissue donor was tested negative for HIV-1, HIV-2, HCV antibodies, HBsAg and syphilis. No test can give complete assurance that infectious agents are absent, so the material must be handled as potentially infectious.
Manufacturer's use statement	For research use only. Not for use in diagnostic procedures.

Purified from human heart tissue rather than expressed, so it presents the native cardiac isoform. Read the donor-screening row: the material must be handled as potentially infectious, and that is a laboratory-safety decision rather than a purchasing one.

Anti-cTnI capture antibody with stated pairing

Manufacturer catalogue L3C00401 · example lot shown: L190101

Product	Mouse monoclonal anti-cTnI — recommended capture antibody
Clone	NI001
Host / isotype	Mouse, IgG1 (hybridoma of Sp2/0 myeloma with Balb/c spleen cells)
Source	Ascites
Immunogen	Human cTnI
Format	Purified, liquid
Purification	Protein A chromatography
Concentration	6 mg/ml
Buffer	10 mM PBS, pH 7.4
Preservative	None
Specificity	Reacts with free cardiac troponin I (cTnI)
Stated applications	cTnI immunoassay, immunoprecipitation, immunohistochemistry, immunoaffinity purification, Western blot
Recommended pair	Capture L3C00401 with detection L3C00402 or L3C00404
Storage & shelf life	-20 °C for 3 years; avoid multiple freeze/thaw cycles

This is the item worth reading closely. The manufacturer names a recommended sandwich pairing — this clone as capture, with a specified detection antibody — which removes one optimisation variable from a development programme. It does not remove the need to verify the pair in your own matrix.

D-dimer — native antigen and two antibody hosts

D-dimer is not a recombinant protein and should not be specified as though it were. It is purified from human material, and its concentration and handling reflect that.

Purified native D-dimer antigen

Manufacturer catalogue L4C00801 · example lot shown: L171101

Product	Purified native human D-dimer antigen
Source	Human serum
Purification	Affinity purified
Concentration	10 mg/ml
Buffer	PBS, pH 7.5, 150 mM NaCl
Preservative	None
Stated applications	Standard in immunoassay; immunogen for antisera production; tracer for iodination
Storage & shelf life	-20 °C for 3 years; avoid multiple freeze/thaw cycles
Manufacturer's use statement	For research use only. Not for use in diagnostic procedures.

Affinity purified from human serum. Because D-dimer in circulation is a family of cross-linked fibrin degradation products rather than one defined molecule, what an assay measures depends on the antigen used to raise the antibodies as much as on the antibodies themselves.

Goat anti-human D-dimer polyclonal

Manufacturer catalogue L3C00703 · example lot shown: L181001

Product	Goat anti-human D-dimer polyclonal antibody
Host / isotype	Goat, IgG
Source	Serum
Immunogen	Human D-dimer antigen
Format	Purified, liquid
Purity	>90% (SDS-PAGE)
Concentration	5 mg/ml (OD280 nm)
Buffer	PBS, pH 7.4
Preservative	None
Stated applications	ELISA and Western blot; working titre to be determined by the user
Storage	-20 °C

Raised against the same antigen, for ELISA and Western blot formats. Working titre is left to the user by the manufacturer, which is standard for polyclonal reagents.

Rabbit anti-human D-dimer polyclonal

Manufacturer catalogue L3C00704 · example lot shown: L190301

Product	Rabbit anti-human D-dimer polyclonal antibody
Host / isotype	Rabbit, IgG
Source	Serum
Immunogen	Human D-dimer antigen
Format	Purified, liquid
Purity	>90% (SDS-PAGE)
Concentration	6.5 mg/ml (OD280 nm)
Buffer	PBS, pH 7.4
Preservative	None
Stated applications	ELISA and Western blot; working titre to be determined by the user
Storage	-20 °C

Second host species against the same antigen. Two hosts for one antigen makes a sandwich format possible without conjugating both reagents.

What these pages do not claim

Questions this page usually raises

Can you send the specification sheet for a specific item before I enquire?

Yes — ask us for the specification sheet and we will send the manufacturer's document for that catalogue number, together with the current lot's Certificate of Analysis if stock exists. If you already hold a lot number, give it to us and we will locate its record.

Why do you give lot numbers for the examples?

Because a specification without a lot number cannot be traced. The lot numbers shown are examples from the manufacturer's published sheets, given so that the figures on this page can be identified and checked — they are not a promise that the same lot will ship. What ships is stated on your quotation and documented on the batch CoA.

The antigen is E. coli expressed. Does that matter for my assay?

It matters if your antibody reads a glyco-dependent epitope, if you are studying the native circulating form, or if you are applying the protein to living cells and endotoxin is a concern. It does not matter for immunisation, for many sandwich assay calibrators, or for applications where only the epitope sequence is relevant. The article on protein formats sets the trade-off out in more detail.

Do you hold these items in stock?

Stock position changes and is confirmed per enquiry rather than published here, because a stale availability claim is worse than no claim. Ask for the item and we will answer with the actual position, including whether an evaluation quantity is available.

Can you supply material released under a formal quality system?

Some requirements the manufacturer can meet and some it cannot, and the honest answer depends on the item and on exactly what your programme needs to document. State the requirement at the first enquiry — for example a particular certification, a batch-release document in the manufacturer's name, or a regulatory filing package — and we will confirm what is possible before you invest time in an evaluation.

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