Haptoglobin Typing ELISA Assay


The Haptoglobin Typing ELISA is intended for use for diabetic patients only, for the qualitative determination of Hp phenotypes (Hp 1-1, Hp 2-1, or Hp 2-2) in human serum/plasma. The Haptoglobin Typing ELISA is for research use only and not for use in diagnostic or clinical procedures.

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Haptoglobin Typing ELISA Assay

The Haptoglobin Typing ELISA Assay is For Research Use Only

Size: 1×96 wells
Sensitivity: See Package Insert
Incubation Time: 1.5 hours
Sample Type: Serum, plasma
Sample Size: 15 µL
Alternative Names: Hp Typing ELISA

Assay Background

Haptoglobin (Hp) is a normally occurring acute phase serum protein whose primary physiological role is to scavenge free hemoglobin (Hb), a potent oxidizing agent, from the circulation. Free Hb, released during hemolysis of red blood cells, promotes the accumulation of hydroxyl free radicals which can cause oxidative damage to tissues. Hp acts as an antioxidant by first forming complexes with Hb and then clearing the complexes from the circulation by uptake via the CD163 macrophage receptor.
Hp is polymorphic in man and occurs as either one of three phenotypes, Hp 1-1, Hp 2-1, or Hp 2-2. The prevalence of the three phenotypes of Hp is 16% Hp 1-1, 48% Hp 2-1, and 36% Hp 2-2. Substantial evidence supports the pathogenetic role for the Hp 2-2 phenotype. First, the clearance of the Hb/Hp complex is Hp phenotype dependent with Hp 1-1/Hb complexes being cleared more efficiently than Hp 2- 2/Hb complexes. Second, the Hp 2-2/Hb complex is an inferior antioxidant compared to the Hp 1-1/Hb complex in studies measuring conjugated diene formation of linolenic acid or TBARS formation by oxidized LDL. Third, Hp 1-1 is more efficient in preventing heme release from Hp/Hb complexes than Hp 2-2, a finding that may help explain differences in antioxidant capabilities between the different Hp types. Finally, recent studies show impaired reverse cholesterol transport in diabetics carrying the Hp 2-2 genotype, presumably due to the binding of Hp 2-2/Hb complexes to HDL followed by subsequent iron-mediated oxidative damage. The presence of the Hp 2-2 phenotype in diabetic individuals predicts cardiovascular risk. Several longitudinal studies have established that the Hp 2-2 phenotype is an independent risk factor for cardiovascular disease in type 1 and in type 2 diabetics. Although the distribution of Hp phenotypes is not different in individuals with or without diabetes, the Hp 2-2 phenotype was shown to be a risk factor only in patients with diabetes. This may occur because in a diabetic patient, glycosylation of hemoglobin and the reduction of macrophages expressing the CD163 receptor may contribute to the increase in oxidative stress and tissue damage. It has been shown that the oxidation of LDL by glycosylated hemoglobin is not completely blocked by binding to Hp and the impaired removal of the complexes results in their localization in HDL particles. This increased oxidation of lipoproteins by the Hp 2- 2/Hb complexes likely contributes to the development of vascular complications in diabetics.

Related Products

Human Haptoglobin ELISA Assay
Mouse Haptoglobin ELISA Assay
Human Hemoglobin ELISA Assay

Additional Information

Assay Principle

• Haptoglobin (Hp) Typing ELISA plates are supplied coated with purified monoclonal antibody (mAb) directed against Hp.
• The serum to be tested is diluted and incubated in the Hp ELISA plate. In this step Hp in the serum binds to the immobilized antibody.
• Non-bound Hp is removed by washing.
• Horseradish Peroxidase (HRP) conjugated monoclonal antibody to Hp is added. Note: the same mAb in the unconjugated form was used to coat the microtiter wells. Since Hp 1-1 is dimeric, at most only one HRP conjugated mAb can bind per dimer attached to the well. However, Hp 2-1 and Hp 2-2 are polymeric and can potentially bind 2-8 HRP conjugated mAbs.
• Unbound conjugate is removed by washing.
• TMB substrate reagent is added resulting in the development of a blue color.
• The blue color development is stopped with the addition of stop solution changing the color to yellow.
• Absorbance is measured using a spectrophotometer at 450 nm.
• The absorbance of each sample is compared to a user-calculated cut-off to determine its Hp phenotype.

Package Inserts

Please note: All documents above are for reference use only and should not be used in place of the documents included with this physical product. If digital copies are needed, please contact us.

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