Materials required but not provided

Serum specimens

Freshly collected sera intended for H. pylori-testing should be stored at 2 – 8 °C before use.

If it is intended to store the specimens for periods in excess of 48 hours they should either be preserved with 0,1 % sodium azide or frozen at –20 °C.

Contaminated, haemolysed or excessively lipaemic sera may give aberrant results.

Heat inactivation at 56 °C should not affect the test results.

Instruction for reagent preparation and storage

All unopened components can be used up until the date printed on the outer box, provided they are stored at 2 ‑ 8 °C.

The strips should be stored at room temperature after first opening.

Reconstitution of the serum-dilution-washing buffer (SDW)

Add 20 ml concentrated washing buffer to 180 ml distilled water (= 200 ml). Mix well. Working strength solution is stable up to two weeks at 2 – 8 °C.

Conjugate

While the first incubation is in progress, dilute the conjugate:

It is not necessary to bring the conjugate to room temperature prior to dilution. It is recommended to take the conjugate out of the refrigerator, draw the needed amount from the vial and put the remaining conjugate back into the refrigerator immediately. Working strength solution is stable for one hour at room temperature (22 °C).

 ASSAY PROCEDURE

1. Take the required number of strips out of the tube with tweezers and put them the right side up in their respective channels of the incubation tray. The upper side of the strips (with the strip number and the front marker line) must never turn down during all incubations. If that happens while adding reagents or buffers, turn the strip back the right way up immediately with tweezers.

2. Add 2 ml blocking-buffer (mix well prior to use) to each strip. Take care that all strips are completely covered with fluid. That is important for all other steps of the procedure, too.

3. Incubate for 15 min on a shaker. Take care that the fluid is mixed well by the shaking but cannot contaminate the adjacent channel. That is especially important for the following serum incubation!

4. Dilute serum specimens 1 : 51 with SDW buffer (add 20 µl specimen to 1.000 µl SDW buffer and mix well).

5. Discard the blocking-buffer by decanting from the incubation tray. The strips are completely re-hydrated now and will stay adhesive to the bottom of the channels during decanting. Add 1 ml diluted serum specimen to their respective channels and incubate for 40 minutes on the shaker.

6. Wash all strips 4 times. Sufficient washing is very important:

7. Add 1 ml freshly prepared conjugate to each strip.

8. Incubate for 30 minutes on the shaker.

9. Wash all strips 4 times as described in step 6. Aspirating can be replaced by decanting.

10. Wash all strips with distilled water (don't incubate). This extra washing improves the development of the bands and reduces background staining.

11. Add 1 ml substrate to each strip.

12. Incubate for 10 – 15 minutes on the shaker.

13. Add 1 ml stop solution to each channel, shake gently for some seconds and decant. Add 1 ml stop solution again, shake for 3 minutes and decant.

14. Remove the strips with tweezers from the tray and dry them on absorbent paper. Analyse the band pattern according to the procedure on the next page.

For documentation store the strips protected from light.