Antibody Evaluation (Immunofluorescence-based)

Immunofluorescence-Based test strip was prepared with K50f4-K56t1 antibody (30 Abbott calibrators, Concentration: 5-200 ng/ml, R² >97%)

Accuracy
The quality control samples with concentration of 25 ng/ml-30 ng/ml and 70 ng/ml-80 ng/ml respectively were required to repeat test three times. B= (M-T) / T×100% (B: Relative Standard Deviation, M: Average, T: Concentration)

Repeatability
The quality control samples with concentration of 25 ng/ml-30 ng/ml and 70 ng/ml-80 ng/ml respectively were required to repeat test over 10 times. CV= (S /) ×100% (CV < 15% as indicated in the following table)

Antibody Evaluation (Immunological Turbidimetry)

R1: Buffer
R2: Combination of K50f4-K56t1 matched pair antibody and latex particals
Sample: PG I calibrator
Equipment: Hitachi 7080

Linear range

Linear dependence > 99% with concentration between 0-200 ng/ml.

Theoretical value (ng/ml)	Measured value 1	Measured value 2	Average
0.00	2.1	3.54	2.82
25.00	29.22	27.02	28.12
50.00	55.8	52.8	54.3
100.00	108.25	107.36	107.805
200.00	208.76	206.74	207.75

Fig. 3 Linearity range

Antibody Evaluation (Immunological Turbidimetry)

R1: Latex particals
R2: K50f4-K56t1 matched pair antibody
Sample: PG I calibrator
Equipment: Hitachi 7080

Pepsinogen I, the precursors of pepsin, is produced by the gastric mucosa and released into the gastric lumen and peripheral circulation. Pepsinogen consists of a single polypeptide chain of 375 amino acids with an average molecular weight of 42 kD. PG I (isoenzyme 1-5) is secreted mainly by chief cells in the fundic mucosa, whereas PG II (isoenzyme 6-7) is secreted by the pyloric glands and the proximal duodenal mucosa.

Precursor reflects numbers of stomach surface cells as well as glandular cells, and monitors gastric atrophy indirectly. They are also extraordinarily stable because they perform their jobs under the harsh conditions present in the digestive system. The atrophy of the corpus mucosa leads to low synthesis of pepsinogen I and hence its low release into the serum. Serum pepsinogen I indicates function and states of gastric mucosa.