The DxPG80 test is an ELISA (Enzyme-Linked Immunosorbent Assay) for the detection of hPG80 (circulating human progastrin).
The test is intended for professional laboratory use only.
Please note that for greater clarity, we use the name hPG80, referring to extracellular Progastrin.
The test is based on the principle of a sandwich ELISA to measure the concentration of hPG80 in plasma samples that have been collected in EDTA tubes.
Briefly, a capture antibody specific for hPG80 is immobilised on the 96-well plate. The hPG80 present in the calibrators and samples added to the wells will bind to the immobilized capture antibody. The test plate includes calibrators which are used to estimate the level of hPG80 in EDTA plasma samples. The wells are washed and an anti-hPG80 detection antibody coupled to horseradish peroxidase (HRP) is added, resulting in an antibody-antigen-antibody complex. After a second wash, a substrate solution of 3,3',5,5'-Tetramethylbenzidine (TMB) is added to the wells, producing a blue colour directly proportional to the amount of hPG80 present in the initial sample. The Stop Solution changes the colour from blue to yellow, and the wells are read at 450 nm with a microplate reader.
The assay is technically characterised in manual mode by a limit of detection (LoD, 1.0 pM) and a limit of quantification (LoQ, 3.3 pM). The LoD detects the presence of hPG80 and the LoQ gives the concentration at which the assay is quantitative.
Table 1 : Comparative description of hPG80 in Controls (healthy blood donors 18-40 years old at low risk of cancer) and Cancer patients (16 cancers tested, all combined). Reference range are given for a 2.5 (low range) and 97.5 (high range) percentile. IQR: Inter-Quartil Range, 25-75%. SE: Standard Error.
. You et al, EBioMedicine, 2020 Jan;51:102574