SSI DiagnosticaHerredsvejen 23400 HillerødDENMARKT: (+45) 48 29 91 00EAN: 5790 002327452VAT: 37294535
S. sonnei consists of two phases. The two phases can be differentiated morphologically, as phase I occurs in the form of smooth colonies, whilst phase II occurs in the form of rough colonies. It is therefore crucial that a suitable culturing medium is chosen, as the transformation between the two phases is dependent on, among other factors, the concentration of divalent cations. The higher the concentration of divalent cations, the more rough colonies there are (phase II). A patient sample will usually contain both types of colony.The antigen that identifies a phase II colony is a subset of the antigen that identifies the phase I colonies. Phase I colonies will therefore agglutinate in phase I sera, but some phase I strains will also agglutinate in phase II sera. Phase II colonies will agglutinate only in phase II sera.
S. sonnei antiserum is produced by immunising rabbits with killed whole cells from phase 1 or phase 2 bacteria (as above - monoclonal product). The product is supplied in a vial with 3 mL ready-to-use antiserum, sufficient for at least 150 tests.
The Shigella strain is cultured overnight on a selective or a non-selective agar plate. A small colony is transferred to a slide and mixed with a drop of antiserum, and the slide is tilted slowly back and forth. If the bacterial colony has antigens that are homologous with the antiserum used, the cells will form antigen-antibody bonds, and clear aggregates will appear (agglutination). The result is read within 5-10 seconds of mixing. The reading is easiest to perform and clearest if the slide is held up in front of a light source against a black background.
SSI Diagnostica A/SHerredsvejen 23400 Hillerød
Tel.: +45 4829 9100 (switchboard)
Inquiries:email@example.comTel.: +45 4829 9178
Frequently asked questions about S. sonnei fase antisera.
Q: Can I freeze the antibodies?A: Antibodies can be frozen, but the process of freezing and thawing is damaging for the antibodies, and the titer will drop (even though not dramatically) due to decomposition. We have not made further studies on this, and cannot guarantee the stability of the sera, but we have experienced that mostly the titer stays at the same level if a serum only is frozen and thawn once.
Q: Is it possible to reserve antisera from a particular lot?A: Yes, it is possible, if you place an order in advance with the expected total volume for the period. In return we guarantee to keep the reserved lot for you.
Q: Can I order products that do not appear in the catalogue?A: Please send an inquiry. We might have it. Depending on the needed volume, we might be able to develop the requested product. It can be anything from a new pool composition to a new antiserum.