Eagle Biosciences’ COVID-19 IgM and IgG ELISA Assay Kits were recently highlighted in a study. This study evaluated the different tools that have become available for COVID testing and research.


Recent severe acute respiratory syndrome 2 (SARS-CoV-2) known as COVID-19, presents a deadly challenge to the global healthcare system of developing and developed countries, exposing the limitations of health facilities preparedness for emerging infectious disease pandemic. Opportune detection, confinement, and early treatment of infected cases present the first step in combating COVID-19. In this review, we elaborate on various COVID-19 diagnostic tools that are available or under investigation. Consequently, cell culture, followed by an indirect fluorescent antibody, is one of the most accurate methods for detecting SARS-CoV-2 infection. However, restrictions imposed by the regulatory authorities prevented its general use and implementation. Diagnosis via radiologic imaging and reverse transcriptase PCR assay is frequently employed, considered as standard procedures, whereas isothermal amplification methods are currently on the verge of clinical introduction. Notably, techniques such as CRISPR-Cas and microfluidics have added new dimensions to the SARS-CoV-2 diagnosis. Furthermore, commonly used immunoassays such as enzyme-linked immunosorbent assay (ELISA), lateral flow immunoassay (LFIA), neutralization assay, and the chemiluminescent assay can also be used for early detection and surveillance of SARS-CoV-2 infection. Finally, advancement in the next generation sequencing (NGS) and metagenomic analysis are smoothing the viral detection further in this global challenge.

To read more click here.

Oishee MJ, Ali T, Jahan N, et al. COVID-19 Pandemic: Review of Contemporary and Forthcoming Detection Tools. Infect Drug Resist. 2021;14:1049-1082. Published 2021 Mar 17. doi:10.2147/IDR.S289629

Related Products
Coronavirus COVID-19 IgM ELISA Assay Kit
Coronavirus COVID-19 IgG ELISA Assay Kit
COVID-19 Nucleocapsid IgG Quantitative ELISA Assay Kit
COVID-19 S-Protein Specific IgG Quantitative ELISA Assay Kit
COVID-19 Neutralizing Antibody Quantitative ELISA Assay Kit

Osteoprotegerin Biomarker Spotlight

Osteoprotegerin (ORG) is a secreted protein that affects bone turnover and is implicated in heart and kidney disease. It is a glycoprotein of the TNF receptor superfamily 11b (gene name TNFRSF11B). OPG is synthesized as a monomer of 380 amino acids and is assembled as a homodimer within the cell and then secreted mainly as a disulfide-linked homodimer into the extracellular compartment. OPG is produced by many different tissues and cell types including osteoblasts. OPG is a negative regulator of bone resorption by acting as decoy receptor for RANKL, thus neutralizing its function in osteoclastogenesis. This glycoprotein is also involved in the regulation of vascular calcification. A recent study identifies OPG as an independent risk factor for all-cause mortality in patients after kidney transplantation. 982 prevalent kidney transplant (KT) recipients were followed up for all-cause mortality for 6 years. The researchers observed that each 1 pmol/L higher-serum OPG level was associated with a 49% higher risk of mortality.

Association between serum osteoprotegerin level and mortality in kidney transplant recipients. Gupta V et al., 2021. Transpl Int 19. doi: 10.1111/tri.13847. Epub ahead of print. PMID: 33606319.

Osteoprotegerin Related Products

Osteoprotegerin ELISA Assay Kit
Sclerostin ELISA Assay Kit
Periostin ELISA Assay Kit

New Insulin ELISA Assay Kits

Eagle Bioscience’s has extended their line of insulin assays! We now offer a wide range of Insulin ELISA Assay Kits that measure insulin concentration in a number of different species samples. These new kits include the Ovine Insulin ELISA Assay Kit, Equine Insulin ELISA Assay Kit, Porcine Insulin ELISA Assay Kit, Canine Insulin ELISA Assay Kit. These kits are highly sensitive, reliable, and easy to use.

More about insulin:

Insulin is a peptide hormone, produced by beta cells of the pancreas. Enzymatic cleavage of proinsulin results in the production of equimolar amounts of insulin and C-peptide in circulation. Insulin is central to regulating carbohydrate and fat metabolism in the body.  Excessive amounts of insulin are associated with excess amounts of glucose in the system. High levels of insulin are known to cause weight gain, water bloating, high blood pressure, magnesium deficiency and an increase in the amount of inflammatory compounds in the blood, which causes blood clots and blood vessel damage. Insulin, when insufficiently produced, results in diabetes mellitus. In most cases, a high fasting insulin level is consistent with insulin resistance symptoms, but in some cases, it can be caused by more serious conditions such as Cushing’s syndrome, acromegaly or possibly insulinoma.

Related Insulin ELISA Assay Kits:

Proinsulin ELISA Assay Kit

Insulin ELISA Assay Kit

Insulin Ultrasensitive ELISA Assay Kit

If you are looking for any other specific related products, or have any questions about our offerings contact us here.

iLite Assay Ready Cells

iLite® Assay Ready Cells are developed by our partners at Svar Life Science. iLite technology is based upon a reporter gene assay format, modified and adapted for applications during the whole drug development cycle as well as for monitoring of biological drugs. These cell lines can be developed for any biopharmaceutical target and assays for drug potency, i.e. drug activity, and neutralizing antibodies (NAbs) can easily be set-up using the same cell line. The Assay Ready cells are genetically engineered to be used with a reporter gene assay technique for detection the the drug potency and the NAbs.

A Message from SVAR about iLite:

“Many therapeutic antibodies that are used to treat common disorders, such as cancer and autoimmune diseases work – at least in part – by activating ADCC.

Our reporter gene-based iLite® ADCC bioassays offer a convenient and powerful way of measuring the ability of an antibody to elicit ADCC.

Read our new white paper and learn about the performance of our ADCC bioassays and how they compare to a leading competitor in terms of sensitivity and dynamic range.”

Download the White Paper here.

Find all of the iLite products offered on the iLite Assay Ready Cells product page.

DHEA ELISA Publication

Evidence for fasting induced extra-adrenal steroidogenesis in the male brown anole, Anolis sagrei

The Eagle Biosciences DHEA ELISA was used in a recent study testing if fasting could induce adrenal tissues to produce glucocorticoids (GCs) and dehydroepiandrosterone (DHEA) to coordinate different physiological processes.


Glucocorticoids (GCs) and dehydroepiandrosterone (DHEA) are steroids secreted by the adrenal glands into circulation to effect distant target tissues and coordinate physiological processes. This classic systemic view of steroids has been challenged by evidence that other tissues can independently synthesize their own steroids. Little is known however regarding circumstances that can promote this extra-adrenal steroidogenesis. Here we tested if fasting can induce tissues to increase GC and DHEA synthesis in the brown anole lizard Anolis sagrei. Lizards fasted for eight days lost body mass and increased fatty acid oxidation. Fasting also increased plasma concentrations of DHEA and corticosterone, but not cortisol. Corticosterone concentration within the adrenals, heart, intestines, lungs and liver exceeded that in plasma, with the latter two increasing with fasting. Levels of DHEA in the adrenals and heart were higher than in plasma, but no significant effect of fasting was observed, expect for a noticeable increase in intestinal DHEA. Two steroidogenic genes, the steroidogenic acute regulatory (Star) protein and Cyp17a1, a cytochrome P450 enzyme, were expressed in several tissues including the liver, lungs and intestines, which were increased with fasting. Continued research should aim to test for expression of additional enzymes further along the steroidogenic pathway. Nonetheless these data document potential extra-adrenal steroidogenesis as a possible mechanism for coping with energy shortages, although much work remains to be done to determine the specific roles of locally synthesized steroids in each tissue.

To learn more and read the full publication, click here.

Related Products:

DHEA Saliva Sensitive ELISA

Big Endothelin-1 Biomarker Spotlight

Big Endothelin-1 (Big ET-1) is a protein that is mainly produced by vascular endothelial and smooth muscle cells and cardiomyocytes. Big ET-1 is a precursor to Endothelin (ET), the most potent vasoconstrictor known today. The half life of ET is less than one minute, whereas Big ET-1 is cleared more slowly. Big ET-1 can therefore be determined more easily, and has since been identified as a risk factor for a poor prognosis in patients with atrial fibrillation or coronary artery disease. A current study has shown that plasma concentrations of Big ET-1 is a valuable tool for risk stratification in patients with left ventricular non-compaction cardiomyopathy (LVNC). Other studies have also recognized the effectiveness of Big ET-1 as a predictor for numerous cardiovascular diseases.

Prognostic value of plasma big endothelin-1 in left ventricular non-compaction cardiomyopathy. Fan P, et al. Heart 2020;0:1–6. doi:10.1136/heartjnl-2020-317059

Plasma big endothelin-1 is an effective predictor for ventricular arrythmias and end-stage events in primary prevention implantable cardioverter- defibrillator indication patients. Li XY et al., 2020. J Geriatr Cardiol 28;17(7):427-433.

Plasma big endothelin-1 predicts new-onset atrial fibrillation after surgical septal myectomy in patients with hypertrophic cardiomyopathy. Song C et al., 2019. BMC Cardiovasc Disord 22;19(1):122.

Plasma level of big endothelin-1 predicts the prognosis in patients with hypertrophic cardiomyopathy. Wang Y et al., 2017. Int J Cardiol 15;243:283-289.

Related Products:

Big Endothelin-1 ELISA Assay Kit.
NT-proANP ELISA Assay Kit
NT-proCNP ELISA Assay Kit
BNP Fragment ELISA Assay Kit

If you have any questions regarding our Big Endothelin-1 ELISA Assay Kit or any other kits in the Cardiovascular Assay line, contact us here.

ELISpot Kits

Eagle Biosciences proudly offers a broad range of products in our extensive catalog. In addition to the well known ELISA format, we offer several assay kits in a enzyme-linked immunospot (ELISpot) assay format.


ELISAs use antibodies to detect the presence and concentration of a protein in a liquid sample. In the most common form, antigens are applied to a stable surface (usually a microtiter plate). Then the corresponding antibody, linked with an enzyme, is added to form a complex. Finally, the enzyme’s substrate is added, which produces a measurable reaction, usually in the form of a color change.

ELISpots also utilize antibody-enzyme reactions. However, instead of measuring the concentration of protein in a sample, they measure the number of cells secreting the cytokine of interest in a sample. Antigens are applied to the plate surface, and when samples are added, cells settle on the bottom of the wells. The cytokines secreted by the cells are captured by the surrounding antigens. After the appropriate incubation time, the cells are removed and the secreted cytokine is detected using a detection antibody linked with an enzyme. The enzyme’s substrate is added, producing a reaction. The end result is visible spots on the on the surface of the plate. Each spot corresponds to an individual cell that was secreting the target protein.

The information provided by ELISpot kits is applicable to various fields of study including: transplantation, vaccine development, T-cell regulation analysis, autoimmune disease, cancer, allergy, and viral infections. These kits are highly sensitive and easy to use.

ELISpot Kit Procedure

Our available kits:

IFN gamma ELISpot Assay Kit

Mouse IFN gamma ELISpot Assay Kit

Rat IFN gamma ELISpot Assay Kit

TNF alpha ELISpot Assay Kit

Rat TNF alpha ELISpot Assay Kit

Contact us if you are looking for a specific ELISpot or if you have questions about any of our products.

Calprotectin ELISA

Does Human Milk Fortifier Affect Intestinal Inflammation in Preterm Infants?

Eagle Biosciences’ Calprotectin ELISA Assay Kit was used in a recent study dealing with inflammation of preterm infants in response to human milk fortifier. The Calprotectin ELISA Assay is part of our line of Gastrointestinal Assays which is a line of highly sensitive and specific kits used to detect the concentration of a variety of samples in serum, plasma, tissue, urine, and saliva.


Background: Fecal calprotectin, a recognized marker of intestinal inflammation, is derived from neutrophil migration to a site of inflammation. Introduction of bovine-based human milk fortifier containing intact protein in preterm infants is associated with an increase in fecal calprotectin suggestive of intestinal inflammation. Newer fortifiers contain protein hydrolysates in place of intact protein.

Objective: To measure fecal calprotectin in human milk-fed preterm infants before and after human milk fortification using a fortifier containing hydrolyzed protein.

Methods: Serial stool samples were collected from 24 infants beginning at the first week to 60 days postnatal age. To compare the effect of human milk fortification, samples collected before and after fortification were compared. Infant demographics, diet, postnatal morbidities, and maternal characteristics were recorded.

Results: A total of 401 stool samples were collected from 24 study infants who had a birth weight of 993 ± 277 g (mean ± standard deviation), gestational age 27.5 ± 2.8 weeks, and fortifier initiation at 14 days. Median fecal calprotectin before and after fortification were similar. Calprotectin levels were not correlated with birth weight or gestational age but were inversely correlated with postnatal age (p = 0.005), use of fortifier (p < 0.001), receipt of antibiotics antenatally (p = 0.007) and postnatally (p = 0.008). After adjusting for postnatal age, calprotectin levels were significantly lower following receipt of fortifier (p < 0.001) and postnatal antibiotics (p < 0.001).

Conclusions: The feeding of protein hydrolysate-containing human milk fortifiers does not appear to be associated with increases in a marker of intestinal inflammation.

Click here for the full text.

Related Products

NGAL (Stool) ELISA Assay Kit
S100A8/A9 (MRP8/14, Calprotectin, Mouse/Rat) ELISA Kit
Stool Sample Collection Kit

COVID-19 IgG and IgA ELISA Feature in Recent Study Analyzing Antibody Response to SARS-CoV-2 Exposure and Symptom Onset

A study has been published in Viruses titled Persisting Neutralizing Activity to SARS-CoV-2 over Months in Sera of COVID-19 Patients by B, Flehming et al. This study takes a look at the long term presences of SARS-CoV-2 RNA and IgG and IgA antibodies in three patients diagnosed with COVID-19 over a six month period. This research utilized the COVID-19 Nucleocapsid IgG Quantitative ELISA Assay Kit and the Anti-SARS-CoV-2 IgA (S1 RBD) ELISA Assay offered by Eagle Biosciences. The results of this study indicate that immunity to the virus may persist for a couple of months after onset of symptoms. These findings are consistent with some other studies done with larger cohorts of COVID-19 patients, however similar longitudinal studies should be done in the future to corroborate these findings.


The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19.

Click here for the full text.

To view Eagle Biosciences’ extensive collection of SARS-CoV-2 Assays and other products click here. 

Introducing the FGF-19 ELISA Assay Kit and the Mouse FGF-21 ELISA Kit. These kits are an extension of an expansive FGF Assay line of kits Eagle Biosciences already offers. Fibroblast Growth Factors are a family of cell signaling proteins that are involved in a wide variety of biological processes. FGF-19 and FGF-21 belong to a subfamily of these proteins that function as an important role in nutrient metabolism.

More about FGF-19:

The primary source of endocrine FGF-19 is the ileum, bile acids release into the intestine after a meal to induce expression of FGF-19. Circulating FGF-19 plays an important role in maintaining proper bile acid homeostasis. Several pharmacologic studies in hyperglycemic, obese animal models have shown that FGF-19 can improve metabolic rate and lower serum glucose and hepatic triglyceride and cholesterol levels. Like insulin, FGF-19 functions as postprandial hormone to govern hepatic protein synthesis, glycogen synthesis and gluconeogenesis, but does not stimulate lipogenesis.

More about FGF-21:

FGF-21 has been implicated in the regulation of lipid and glucose metabolism under fasting and ketotic conditions. In murine models, FGF-21 is predominantly expressed in liver, but it also expressed in adipose tissue and pancreatic β-cells. FGF-21 stimulates glucose uptake in adipocytes. It also protects animals from diet-induced obesity when overexpressed in transgenic mice and lowers blood glucose and triglyceride levels when administered to diabetic rodents. When administered daily for 6 weeks to diabetic rhesus monkeys, FGF-21 caused a dramatic decline in fasting plasma glucose, fructosamine, triglycerides, insulin, and glucagon. Furthermore, elevated plasma FGF-21 concentrations in humans appear to be related to the presence of hepatic and peripheral insulin resistance.

Related Products:

FGF-23 C-Terminal ELISA Kit

MedFrontier Intact FGF-23 Assay

FGF Basic ELISA Assay

Intact FGF-21 ELISA Kit

Total FGF-21 ELISA Assay

cTerminal FGF-21 ELISA Kit

N-Terminal FGF-21 ELISA Kit

iLite FGF-21 Assay Ready Cells

If you are looking for any other specific related products or if you have questions about our offerings, contacts us here.