Description

Summary
After Schistosoma japonicum infect organism, the specific antibody against Schistosoma japonicum arise in serum, hereby detecting the specific antibody against Schistosoma japonicum can be the secondary diadynamic criteria.
The test take the Schistosoma japonicum eggs antigen as the solid phase antigen to detect specific antibody against Schistosoma japonicum in serum.

Reagents and contents
1 8× Coated microtiter strips: ready to use
2 1× Conjugate solution: ready to use
3 1× Washing solution: ready to use
4 1× Substrate A solution: ready to use
5 1× Substrate B solution: ready to use
6 1× Sample dilution: ready to use
7 1× Stopping solution: ready to use
Warning: Stopping solution irritates eyes and skin. Keep out of the reach of children. Upon contact with the eyes, rinse thoroughly with water and consult a doctor.
8 1× Positive control: ready to use
9 1× Negative control: ready to use
10 1× Instruction sheet

Test procedure
1 Sample preparation:
Dilute the patient’s serum with sample dilution at 1:100, e.g. 10 μl serum + 1 ml sample dilution, and mix thoroughly.
2 Adding samples and controls
Leave well A1 for reagent blank. Pipette controls and samples as follows:
100μl negative control and positive control respectively, and 100μl diluted samples each into remaining wells.
Incubation at 37℃for 15 minutes. Discard off contents of the wells and add each well of washing solution, fill all wells with distilled water completely, incubate for 15 seconds and discard off. Perform another 4 washing cycles as above. At the end of the washing step carefully remove remaining fluid by tapping the strips on the tissue paper prior to the next step.
3 Adding conjugate solution
Dispense 2 drops into all wells and incubate at 37℃ for 15 minutes. Discard the contents of the wells and wash 5 times as described in step 2.
4 Adding substrates
Dispense one drop of substrate A solution and B solution respectively, incubate at room temperature (37℃)for 10 minutes.
Dispense one drop of stopping solution into all wells. Zero the ELISA microtiter plate reader using the reagent blank well A1. Measure the absorbance at 450 nm.
Results
1 Observation with naked eyes before adding stopping solution
Negative: No apparent blue appears in the sample wells. This indicates that no cysticercus antibody has been detected.
Positive: Apparent blue appears in the sample wells. This indicates that the sample contains cysticercus antibody.
Invalid: If no blue appears in the positive control well or apparent blue is observed in the negative control well, this indicates a possible error in performing the test. The test should be repeated using a new kit.
2 Judgment by microtiter plate reader
Cut-off value = 2.1×A- (absorbance of negative control)
Interpretation of results
A450 (patient) ≥ cut-off: anti- Schistosoma japonicum antibody positive
A450 (patient) ＜ cut-off: anti- Schistosoma japonicum antibody negative.

Notes
1 Always brings all reagents, samples and controls to room temperature before use.
2 Don’t use tap water for washing steps.
3 Recommend to judge result by microtiter plate reader and to set duplicate negative control to reduce deviation