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May 2011


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"ADET (Anders Thorn)" <[log in to unmask]>
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The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
Mon, 16 May 2011 11:09:35 +0200
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Dear Forum,

When you make a screening of different dilutions of a sample for LAL test that cause inhibition of the assay the recovery of the positive product (%PPC recovery) increase with the dilution. Often you will see that the curve (% PPC as function of the dilution) level off when the %PPC recovery is above 100 % (for instance at around 130 % which corresponds to the %PPC recovery of LAL reagent water or WFI tested in your assay) and not when the %PPC recovery is exactly 100 %.

When is a solution considered free for interference in the LAL test? Is it when you dilute your sample so you get a %PPC recovery at around 100 % or is it when you dilute your sample to a degree where the curve (% PPC as function of the dilution) level off (for instance at around 130 %)?

Thanks and best regards,


Anders Thorn

Novo Nordisk A/S

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