Test Catalog

Test ID: IEHCG    
Interference Evaluation Heterophile, Beta-Human Chorionic Gonadotropin, Serum

Method Description Describes how the test is performed and provides a method-specific reference

The specimen will be evaluated for potential heterophile antibody interference in the Roche Elecsys total beta-human chorionic gonadotropin (hCG) immunoassay. Heterophile Antibody evaluation will consist of pretreatment with commercial heterophile antibody blocking reagents, testing on an alternate platform (Beckman Coulter), and serial dilution of the sample.


Heterophile blocking agents consisted of heterophile blocking tube (HBT)-Scantibodies Inc. for the Roche assay, and heterophile blocking agent (HBR)-Scantibodies, Inc. for the Beckman assay. These blockers contain either murine (HBT) or goat (HBR) derived proteins in a buffered salt solution.


Beta-hCG, Quantitative, Serum

The Roche hCG assay is a 2-site immunometric sandwich assay using electrochemiluminescence detection. Patient specimen, biotinylated monoclonal hCG-specific antibody, and monoclonal hCG-specific antibody labeled with a ruthenium react to form a complex. Streptavidin-coated microparticles act as the solid phase to which the complex becomes bound. Voltage is applied to the electrode inducing a chemiluminescent emission from the ruthenium, which is then measured against a calibration curve to determine the amount of hCG in the patient specimen.(Package insert: Roche cobas. Roche Diagnostics; V17 01/2017)


HCG, Alternative Method

The Access Total beta hCG (5th IS) assay is a sequential two-step immunoenzymatic (“sandwich”) assay. A sample is added to a reaction vessel along with a citrate buffer. After an initial incubation, rabbit anti-beta hCG alkaline phosphatase conjugate and paramagnetic particles coated with goat anti-mouse IgG: mouse monoclonal anti-beta hCG complexes are added. The hCG binds to the immobilized monoclonal anti-beta hCG on the solid phase while, at the same time, the rabbit anti-beta hCG alkaline phosphatase conjugate reacts with different antigenic sites on the hCG. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos* 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of total beta hCG in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve.(Instruction manual: Instructions for Use. Beckman Coulter Inc; 2017)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Saturday

Report Available The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 3 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

12 months

Performing Laboratory Location Indicates the location of the laboratory that performs the test