using a HP IIp scanner/densitometer

[Jack M. Bernstein, M.D.]

In article <1994Jun18.234121.1657 at csdvax.csd.unsw.edu.au> exb0431 at csdvax.csd.unsw.edu.au writes:
>From: exb0431 at csdvax.csd.unsw.edu.au
>Subject: Re: using a HP IIp scanner/densitometer
>Date: 18 Jun 94 23:41:21 +1000

>The Cream pc-based image processing system from Kem-en-tec in Copenhagen
>available in Australia uses a HPIIp flat bed scanner to 'grab' the image 
>from gels etc. It's then up to the software to do the 'hard stuff'! So
>I suppose its densitometry.

>A cheaper method is ye olde hand scanner (yes, with a computer) to 'grab'
>the image and then use a good programme. One available from memory is 
>from the USA and called....I think..Biomed! But hand scanners??
>any comments?? a bad case of the DT's and your image is stretched or
>altered slightly.

I've tried hand-scanners. The problem is that you don't resolve your peaks 
very well. A typical hand scanner has 256 shades of gray, a laser, about 
64000. So................ you get very "flat" peaks that underestimates the 
amount in it. Perhaps with back lighting it would be better but I think not.