Search Results

The ALPHA Histoplasma Antigen EIA is an immunoenzymatic sandwich microplate assay for the detection of Histoplasma antigens in urine samples. The ALPHA Histoplasma Antigen EIA is a test which, when used in conjunction with other diagnostic procedures such as microbiological culture, histological examination of biopsy samples and radiographic evidence, can be used as an aid in the diagnosis of histoplasmosis.

The ALPHA Histoplasma Antigen EIA is an immunoenzymatic sandwich microplate assay which detects Histoplasma antigens in urine. Rabbit anti-Histoplasma IgG antibodies bound to microwell plates are used as capture antibodies and biotinylated rabbit anti-Histoplasma IgG antibodies are used as detect antibodies. The positive control is made of buffer spiked with Histoplasma capsulatum antigens and the negative control is buffer only. Standards are made of Histoplasma capsulatum antigens from culture filtrate. The kit contains the 100 Standard, 30 Standard, and 2 Standard that are used to generate a sigmoid calibration curve using a four-parameter fit of the blanked absorbance values versus the assigned EIA Values. R-squared values must be greater than or equal to 0.990. Urine samples are run untreated and undiluted. The samples are added to the microwells coated with the capture antibody and incubated. If the patient specimen contains Histoplasma antigens that are recognized by the capture antibody, those antigens will become bound to the microwell. The wells are washed to remove unbound patient material and biotinylated detection antibody is added to the wells. If Histoplasma antigens are bound to the microwell by the capture antibody, then the detect antibody will also become bound to the microwell. The wells are then washed to remove any unbound detect antibody. For detection, biotin-streptavidin chemistry reagents including 3,3′,5′,5′ tetramethybenzadine (TMB) and stop solution are used. Streptavidin conjugated to horseradish peroxidase (HRP) is added to the microwells. In the presence of the biotinylated detect antibody, streptavidin-HRP will become bound to the plate. The plate is then washed to remove any unbound streptavidin-HRP, and TMB substrate solution is added to the microwells. A blue color develops in the presence of the HRP enzyme. The reaction is stopped by the addition of a stop solution. The optical density (absorbance) is determined with a microplate reader at 450nm or 450nm or 450nm alone. EIA Units for specimens are calculated using a four-parameter curve-fit generated with the 4 standards supplied in the kit.