APS-5 (CAS NO.: 193884-53-6)：A chemiluminescent substrate for immunoassays
1、 Product Overview
Methacryloxyethyltrimethyl ammonium chloride (DMC, 78% solution) is a cationic monomer used primarily as a flocculant in water treatment, a retention aid in papermaking, an antistatic agent in textiles, a conditioning additive in personal care products, and a key building block for functional polymer synthesis.
2、 Basic Product Information
1）Product Name: APS-5
2）CAS NO.：193884-53-6
3）Molecular formula: C21H18ClNNaO4PS
4）Molecular weight: 469.85
5）Structural formula:
6）Purity: ≥ 98%
7）Appearance: White to pale yellow solid
8）Boiling point: >100°C
9）Transport Information: Not dangerous goods
10）Product Manager Email:jessie@coreychem.com
3、 Frequently Asked Questions (FAQ)
Question 1:Please describe the basic physical characteristics of APS-5（CAS NO.: 193884-53-6）.
At room temperature, this product appears as a white to pale yellow powder. Its molecular formula is C₂₁H₁₈ClNNaO₄PS, with a molecular weight of 469.85. In terms of solubility, it is readily soluble in water and in buffered systems with neutral or slightly alkaline pH, but has low solubility in common organic solvents. The product is relatively stable in the solid state; however, once prepared as an aqueous solution, it is prone to hydrolysis and should not be stored for prolonged periods. The recommended storage conditions are: at –20 °C, protected from light and moisture, in a sealed, dry container.
Question 2:What are the key advantages of this product in practical applications?
This product is primarily used as a chemiluminescent substrate in immunoassay systems utilising alkaline phosphatase (ALP) as a marker. Its key advantage stems from the 9,10-dihydroacridine group in its molecular structure—under the catalysis of ALP, this group rapidly releases photons, generating a sustained, stable and high-intensity chemiluminescent signal. Owing to its high sensitivity, high luminescence intensity and long luminescence duration, this product is widely used in applications such as ELISA assays, phosphatase activity assays and gene chip research.
Question 3:What role does the APS-5 play in the chemiluminescence detection process?
This product is one of the key reagents in chemiluminescent immunoassays. In the presence of alkaline phosphatase (ALP), the 9,10-dihydroacridine group in the APS-5 structure undergoes a catalysed reaction, rapidly releasing photons with a peak emission wavelength of approximately 430–450 nm. The amount of photons released is directly proportional to the concentration of ALP in the solution; consequently, it can be used for the quantitative analysis of antigens or antibodies. The reaction reaches a plateau within a few seconds, and this plateau persists for a relatively long time, making it highly suitable for ultramicro-assays.
Question 4:What precautions should be taken regarding the storage and operation of the APS-5?
As the aqueous solution of APS-5 is prone to hydrolysis, particular care must be taken during storage and handling. It is recommended that the solid powder be stored at –20 °C in a sealed, dry container, protected from light and moisture; it can be stored stably for more than two years. Once prepared as a liquid, the reagent should be allowed to return to room temperature (22–35 °C) before use; exposure to strong light should be avoided at all times, as even brief exposure can lead to a significant increase in background signal. The liquid should not be frozen; it is recommended that it be used as soon as possible after preparation.
Question 5:How does a product’s concentration or formulation affect its effectiveness?
In practical applications, the APS-5 is typically formulated as a working solution; the type of surfactant used in the formulation has a significant impact on signal stability. Studies have shown that formulations containing IGEPAL, TRITON and BRIJ surfactants exhibit signal loss of less than 10 per cent after 15 months’ storage at 4 °C, demonstrating superior stability to formulations containing TWEEN® 20. Furthermore, the pH of the working solution has a considerable impact on the assay performance; APS-5 performs best under high pH conditions of 9.5–10.0. Prior to use, ensure that the microplates, reagents and buffers are all at a stable room temperature (20–25 °C) to guarantee the reproducibility of the assay results.
4、 Application Cases
Application 1:The use of APS-5 (CAS No.: 193884-53-6) in ELISA Assays
In the field of enzyme-linked immunosorbent assays (ELISA), APS-5 is used as a highly sensitive chemiluminescent substrate in alkaline phosphatase (ALP)-labelled detection systems. When ALP dephosphorylates APS-5, the substrate rapidly decomposes and releases photons; the luminescence intensity is directly proportional to the amount of ALP, thereby enabling the quantitative detection of antigens or antibodies at extremely low concentrations. APS-5 is widely used in the sandwich ELISA format for the detection of tumour markers, infectious disease antigens, hormones and other biomarkers, with sensitivity reaching the femto-flicker level.
Application 2:The use of this product in gene chip and DNA array research
In gene chip and DNA microarray research, this product serves as an ultra-sensitive luminescent probe for the detection of nucleic acids following hybridisation. Once the target DNA or oligonucleotide has hybridised and bound to the ALP-labelled reporter molecule, the addition of APS-5 generates a chemiluminescent signal that can be captured by a CCD camera or X-ray film. This reagent is capable of detecting alkaline phosphatase at concentrations as low as 10⁻¹⁹ mol and enables rapid, high-throughput analysis of gene mutations and expression patterns on nylon membranes and glass slides.
Application 3:The use of this product in Western blotting
In Western blotting applications, APS-5 acts as a chemiluminescent substrate to visualise proteins immobilised on a membrane. Once the target protein has been bound by an ALP-labelled secondary antibody, the addition of APS-5 triggers a light signal, which can be recorded on X-ray film or via a digital imaging system. Its rapid signal kinetics—reaching peak intensity within seconds—and prolonged luminescence duration make it suitable for detecting low-abundance proteins, whilst offering a high signal-to-noise ratio.
Application 4:The use of this product in the detection of marker genes
In reporter gene assays, particularly those utilising secreted alkaline phosphatase (SEAP) as the reporter gene, APS-5 enables non-invasive, quantitative measurement of gene expression. Cells transfected with the SEAP reporter gene construct secrete the enzyme into the culture medium, and its activity can be detected by adding APS-5. The resulting chemiluminescent signal is directly correlated with promoter activity, enabling researchers to study weak promoters, signal transduction pathways and drug responses, and is suitable for high-throughput screening. This assay offers sensitivity in the femtocoule range and is less susceptible to temperature fluctuations than conventional substrates.
Application 5:The use of this product in point-of-care testing (POCT) and clinical diagnosis
In rapid testing and clinical diagnostic platforms, APS-5 serves as a key signal-generating reagent for rapid, quantitative immunoassays. It produces a stable, high-intensity luminescent signal within two minutes of the addition of the substrate and is compatible with tube-based, plate-based and POCT chemiluminescent detection systems. This reagent is particularly valued in diagnostic kits for biomarkers associated with infectious diseases, endocrine disorders and cardiovascular diseases, as these applications demand strict requirements for speed and sensitivity.
5、 Safety and Storage
1）Long-term storage: It is recommended to store at -20°C in a light-protected, moisture-proof, airtight and dry environment.
2）Short-term transport: It is recommended to store at 0–8°C during short-term transport and to store at -20°C upon receipt.
3）Repackaging recommendations: To avoid repeated freeze-thaw cycles, it is recommended to store the product after repackaging.
6、Product Manager Information
Product Manager: Jessie Liu
Email: jessie@coreychem.com
