> I think that the answer is to do both total protein and albumin on samples
> prior to electrophoresis, and compare the albumin with that derived from
> the electrophoresis result.
>
> This will show up the occasional discrepancy due to cryoprecipitation
> prior to receiving the sample, and also due to undersampling or other
> errors on your TP/Alb analyser (which can often be unrelated to the IgM /
> cryoglobulin problem).
>
> In this lab, we only run one gel per day (Sebia beta1-beta2 gels), so the
> extent of cryo- IgM loss is variable. Our usual cryo patient is usually
> recognisable by a precipitate on the origin (this might not be so obvious
> if you are not using b1-b2 gels).
>
> Our normal procedure is to subtract the Alb from the TP, delete the
> albumin band when scanning, and thus proportion the globulins over the
> difference.
>
> For samples with cryoglobulins, we do not edit out the albumin peak, but
> we do edit out any spike due to precipitate on the origin.
>
> For calculation, we put the percentage for each peak, along with the
> external TP and albumin, on to an Excel spreadsheet.
> This calculates the normal globulin fractions by comparison with the
> albumin band, and adds leftover concentration to the monoclonal
> cryoglobulin. This gives consistent results, regardless of the interval
> and extent of loss by cryoprecipitation between collection and
> electrophoresis. You can use fluidil if you like, but this relies on the
> sample being mixed to include cryoprecipitate. It also assumes that no-one
> else in the lab has enriched the serum by taking off aliquots without
> mixing.
> Our procedure does assume that the TP and albumin assays are done soon
> after collection, and that loss by precipitation is negligible at this
> stage.
>
> Attached: .xls file
>
> I hope that this helps.
>
> Richard Scarff
> Biochem,
> Royal Perth Hospital
> Western Australia
>
>
> <<Cryocalc.xls>>
>
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