The principle of the following enzyme immunoassay test follows the typical competitive binding scenario. Competition occurs between an unlabelled antigen (present in standards, controls and patient samples) and an enzyme-labelled antigen (conjugate) for a limited number of antibody binding sites on the microplate. The washing and decanting procedures remove unbound materials. After the washing step, the enzyme substrate is added. The enzymatic reaction is terminated by addition of the stopping solution. The absorbance is measured on a microtiter plate reader. The intensity of the colour formed is inversely proportional to the concentration of free testosterone in the sample. A set of standards is used to plot a standard curve from which the amount of free testosterone in patient samples and controls can be directly read. The ALPCO free testosterone kit utilizes a highly specifi c rabbit anti-testosterone polyclonal antibody at a low binding capacity (Keq x concentration) to keep minimum disturbances of the testosterone-protein equilibrium. The other components in the test system are also optimized in order to not alter the original free testosterone concentration.
1. What percentage of your IgE allergy testing panel consists of molecular allergens rather than allergen extracts? The ALEX2 IgE allergen panel consists of 117 extracts and 183 molecular allergens. This represents the largest panel of molecular allergens on the market, including 50 unique...
Cases of food and environmental allergies have been increasing over the last decade. While conservative estimates suggest IgE-mediated allergy affects 6-8% of children and 2-3% of adults, some estimates are as high as 30%.3, 2 Symptoms can range from mild to severe and include itching, hives,...
Food sensitivity or food intolerance involves a non-allergic response to a food or food additive. In a recent on-line survey conducted in the U.S., 24% of adults aged 18 to 79 reported a food intolerance. While a food allergy is typically mediated by IgE antibodies, adverse reactions to food...
In a head-to-head comparison of FDA-cleared assays and a novel ALPCO method, investigators observed wide variability in specificity and false-positive rates across platforms, raising important questions about standardization and clinical interpretation.
July 22, 2025 – Salem, NH – NuvinkaDx, a leading innovator in diagnostic solutions, today announced two significant product and regulatory milestones from its operating companies, GeneProof and ALPCO.
Energy homeostasis is a focus of research into diabetes and obesity. Read about how our assays in this area can assist both academic and industry researchers.
Complement System Solutions for Drug Development and Clinical Research Datasheet
The complement system is essential to innate immunity from a variety of diseases. ALPCO’s full range of complement system immunoassays can drive discovery.
Melatonin Products for Sleep Disorder-Related Research Datasheet
The melatonin hormone affects the circadian rhythm and sleep-wake cycle. Find out about our immunoassays and products that explore melatonin and sleep disorders.
