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From: dbk@aberystwyth.ac.uk
Newsgroups: bionet.general
Subject: Re: optical density
Message-ID: <9104021108.AA17480@uk.ac.aber.aberda>
Date: 2 Apr 91 11:08:06 GMT
References: <9103311340.AA03751@genbank.bio.net>
Sender: daemon@genbank.bio.net
Lines: 6

OD and Absorbance are *NOT* the same. Absorbance refers to the absorption
of light *BY A CHROMOPHORE*. OD refers to the amount of light that sets
out from the source but doesn't reach the detecctor. In biology, the usual
reason is that it is *SCATTERED* (mainly elastically), not that it is
absorbed. Hence the difference in terminology. As Michael Caine might say,
"not many people know this".