This experimental method was obtained from the official website of the Fourth Military Medical University
Operation method
Bacterial Fertilizer Reaction Experiment
Principle
The test tube agglutination reaction is a semi-quantitative agglutination reaction. It is commonly used to determine the presence or absence of corresponding antibodies and their content in the examined serum with known antigens to assist clinical diagnosis or for epidemiological investigation and analysis.
Materials and Instruments
Typhoid "H" strain, Typhoid "O" strain. Move 1. Take 14 clean small test tubes and arrange them in two rows on the test tube rack, with 7 tubes in each row numbered sequentially with a crayon, and add 0.5 ml of saline to each tube. Caveat Observe without shaking the test tube to avoid dispersion of the agglomerates Common Problems 1. There is no agglutination in the control tube, and the liquid in the tube is still turbid. However, if left for a long time, the bacteria pile up in the bottom of the tube into small dots, a negative reaction. For more product details, please visit Aladdin Scientific website.
Diagnostic serum, saline.
Small test tubes. Straws.
2. Add 0.5 ml of 1:10 diluted typhoid "H" serum into the first tube of the first row, make the serum and saline mix thoroughly, and then suck out 0.5 ml into the second tube, and then suck out 0.5 ml into the third tube after the same mixing. And so on, diluted to the 6th tube, from the 6th tube sucked out 0.5 ml discarded. At this point, the serum dilution from tube 1 to tube 6 was 1:20, 1:40, 1:80, 1:160, 1:320, 1:640. tube 7 was used as a control without serum.
3. In the same way, pipette 1:10 dilution of S. typhi "O" serum into the second row of the first tube, and in turn, as above to be diluted.
4. Use a pipette to suck typhoid fever "H" bacteria, add the first row of tubes in each tube 0.5 ml, at this time the serum dilution doubled.
5. In the same way in the second row of tubes to add typhoid fever "O" bacteria 0.5 ml.
6. Vibration of the tube mixing, put 37 ℃ water bath box in 2 ~ 4h or 37 ℃ incubator overnight, the next day out of the observation results.
2. Compared with the control tube, the test tube can be seen at the bottom of the tube with different sizes of round pieces of uneven edges of the agglutination, the supernatant is clear and transparent or turbid to varying degrees. The strength of agglutination can be indicated by the "+" sign as follows:
"++++" agglutination is very strong, the liquid in the tube is completely clarified, and the agglutinated mass completely sinks to the bottom of the tube;
"++++" agglutination is strong, the liquid in the tube is not completely clarified and slightly turbid, and the agglutinated mass sinks to the bottom of the tube;
"++" agglutination of medium strength, the liquid is semi-clarified, agglutination block sinks to the bottom of the tube;
"+" agglutination is weak, the liquid in the tube is turbid, a small amount of agglutinated masses sink to the bottom of the tube;
"-" no agglutination, the liquid in the tube is equally turbid as in the control tube, no agglutinated masses.
3. Record the results of observation and determine the agglutination effect. Usually can produce obvious agglutination (+ +) of serum greater than the dilution as the serum agglutination potency. If the lowest dilution of serum (i.e., tube 1, 1:40) is still not agglutinated, it should be reported as less than 1:40. If the highest dilution of serum (i.e., tube 6, 1:1280) is still fully agglutinated, it should be reported as having a potency higher than 1:1280.