Shigella serum, 3 ml, SSI Diagnostica, Denmark

Application

SSI Diagnostica shigella immune sera are intended for serotyping of Shigella strains by agglutination reaction on a subject glass.

 Description

Polyclonal shigella immune serum against dysentery sticks, Fleksner shigella, and Boyd shigella are grown in rabbits. Immune sera against shigella sonnei are monoclonal antibodies (obtained during immunization of mice and fusion of spleen cells with mouse myeloma cell lines). Immune serums are supplied in bottles of 3 ml (sodium azide for preservation).

 Cross-reactions were eliminated by absorption.

 Principle

When the bacterial culture is mixed with a specific immune serum directed against the components of the outer membrane of the bacterium, the cells are combined with each other through the binding of the antigen-antibody to form aggregates (agglutination). This, as a rule, is visible to the naked eye in the form of lumps in the suspension.

Limitation

Latex reagent is intended for serotyping of pure cultures of capsulated pneumococci.

Materials that are needed but not included in the set

• Selective or non-selective agar medium (eg meat peptone agar)

• Inoculation loop or toothbrush

• Object glass

• Physiological solution, pH 7.4

• Incubator 35-37 ° C

Procedure

General

The physiological solution is used as a negative control, and it should be negative. If the negative control is positive (agglutination), the strain automatically agglutinates, that is, O rough.

1. Shigella strain is grown at 35-37 ° C overnight in non-selective or selective agar medium.

2. Apply a small drop of immune serum (approximately 20 μL) to the slide glass.

3. Transfer the cultures from several colonies to the drop of the immune serum and mix well. The amount of culture should be sufficient to give a distinct, muddy-colored color. Use an inoculation loop or toothpick.

4. Carefully incline the glass for 5 - 10 seconds.

5. The reaction is read by the naked eye, holding the glass in front of a light on a black background (indirect light).

6. Positive reaction is considered as visible agglutination. Negative reaction is the preservation of mud-milk homogeneity. Late or weak agglutination should be considered a negative result.

Problems with agglutination

If the Shigella culture is agglutinized badly or if it does not agglutinate at all, place it in a saline solution and boil in a water bath for 15-30 minutes. Then, cool the slurry and test it in the physiological solution to determine if it is rough. If the suspension is not rough, use it to determine agglutination in the immune serum.

Storage and shelf life

Store at 2-8 ° C in a place protected from light. The expiration date is on the package. Occasionally, after prolonged storage, turbidity is observed due to precipitation of lipoproteins. Sediments and / or contamination can be removed by centrifugation (10,000 g) followed by sterile filtration (0.22 μm).

Delivery time: 5 days

Information updated: 03.03.2018