Opened 13 years ago

Closed 13 years ago

#32 closed enhancement (fixed)

Lf - Limit of Flocculation for Tetanus antigen amount

Reported by: Gunther Schadow Owned by:
Priority: major Milestone: Revision 1.9
Component: Keywords:


This unit is being requested by CBER for "quantity of toxoid as assessed by flocculation".

We are still waiting for a definition.

But likely it is just another arbitrary unit. So we can assign [Lf].

I have given push-back, to get thinking about SI units instead, but of course this won't happen any time soon.

Electronic listing depends on this, so we will have to proceed.

Attachments (1)

Lyng_Biologicals_1990.pdf (705.1 KB) - added by Gunther Schadow 13 years ago.

Download all attachments as: .zip

Change History (3)

comment:1 Changed 13 years ago by Gunther Schadow

Here is a decent definition:

The unit “Lf” is called the "Limit of Floculation" or "limes flocculationes". It is based on an antigen-antibody precipitation assay and used predominantly for Tetanus and Diphteria toxoid quantification (but other antigens as well.) The limes flocculationis is the amount of an antibody (measured in international units) which equilibriates the antigen present such that the antigen-antibody complexes precipitate (flocculate). [Source: Schwanig M. Diphtherie und Tetanus: Wie haufig braucht der Mensch Boosterdosen? in: Alte und neue Impfstoffe in Deutschland. Grundlagen fur kunftige Entscheidungen, 27-33, 2001, Infomed Medizinische Verlagsgesellschaft mbH, Berlin.

comment:2 Changed 13 years ago by Gunther Schadow

Resolution: fixed
Status: newclosed

done [33172]

Changed 13 years ago by Gunther Schadow

Attachment: Lyng_Biologicals_1990.pdf added
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