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There is no problem with dimensions here, but lots of
chances for confusion!
As Henry rightly shows, volume is length cubed (L^3).
But the dimensions in each case are M x L(-3) x T(-1)
(M/L^3/T, more easily thought of as: mass or moles per
volume per hour).
There is room for confusion in fact that the dimension L
(length) looks the same as volume L (Litres), and that the
order of hours and litres in the units are swapped around.
So: Forgetting all that, the simple conversion is to take
nmol/h/L and multiply by the molecular weight of the renin
substrate used (nmol to ng) and divide by 1000 ('per L' to
'per mL'). This gives ng/mL/h (=ng/h/mL).
John Duley
Purine Research Laboratory
Guy's Hospital
London SE1 9RT (GB)
----------------------------
On Tue, 8 Jan 2002 21:01:09 +0000 Dr Henry Chandler
<[log in to unmask]> wrote:
> In message <"/GUID:A4148CD82204D6118B900008C73385E1"@MHS>,
> [log in to unmask] writes
> > Does anyone have a conversion factor to convert renin activity
> >from nmol/h/L to ng/ml/h? Thanks in advance.
> >
> >Brian Shine
>
> Doesn't a conversion factor have a problem with dimensions?
> One measure is (M X L^3)/T the other is (M X T)/L^3!
> Sorry about the lack of square brackets which are often used, I'm unsure
> of the character sets used by various mail readers.
>
> --
> Henry Chandler
