FWD: (1) Estrogen receptor assays & (2) the nervous system

les.davies at a1.cbr.hhcs.gov.au les.davies at a1.cbr.hhcs.gov.au
Tue Nov 5 18:16:05 EST 1996


From:	NAME: Les Davies
	FUNC: Therapeutic Goods Admin
	TEL: (06)289 7182 - MDP 88 <DAVIES LES at A1@CBR>
To:	mx%"bioforum at net.bio.net"@cnb09w at mrgate@cbr

Message-id: D752IOD2V16Y
From:	NAME: Les Davies
	FUNC: Therapeutic Goods Admin
	TEL: (06)289 7182 - MDP 88 <DAVIES LES at A1@CBR>
Subject: (1) Estrogen receptor assays & (2) the nervous system
Date:	04-Nov-1996
Posted-date: 04-Nov-1996
Precedence: 1
To:	mx5"biosci-request at net.bio.net"@cnb09w at mrgate@cbr

(1) Estrogen receptor assays

Noted a reply to Raymond Pierre (from JS Amenta?) about receptor binding
assays for estrogen receptors - the comment that the point is "to inhibit
non-specific binding and not affect the specific receptor binding" is not
really correct - non-specific binding is not 'inhibitable'.  In receptor
binding assays, an excess of a known receptor binding compound is added (to a
separate set of assay tubes from the control binding tubes) to make sure that
specific receptors are fully saturated and then no tritiated label from the
probe ligand (trace concentration at or below the Kd) can bind; therefore,
what radioactivity is counted once the receptor prep is isolated from these
tubes is due to non-specific binding eg. physical entrapment of radioactive
incubation solution in membrane folds, blebs etc of the receptor preparation,
plus that not adequately washed off the filter or whatever is used to
separate the receptor prep. from the aqueous incubation solution.   There is
a need to ensure that the concentration of the non-specific displacer is high
enough to make sure all the specific binding sites are blocked.  (The point
that the concentration of a known receptor inhibitor should not be too high
could be true in the case of a receptor prep. in which it was known that
there were two different receptor types which bound your radioactive ligand
and in which you were trying to selectively block one with a not-so-selective
inhibitor, in order to measure the other.)

(2) the nervous system

Re the interesting summary of the human brain (from Melissa M to
'strangeone'), note  the spelling of myelin, hence myelinated , not'
mylenated' - or is this US spelling?!



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