Stefan Kahlert UZS13B at
Mon Sep 19 11:19:57 EST 1994

Hi everybody,
Ram Balaraman thinks it's funny to pick up e-mail addresses of biologists
from this newsboard and answer their questions with disgusting comercials.
I asked that guy what he intents besides making money, but anything but
putting an order seems not to be worth an answer from him.
I think this abuse of the internet is worth a little bit of punishment,
but I don't know how to tell my IBM to resend that trash every 20 seconds
(certain lawyers know that kind of "mails").
Has anyone a better idea how to react or can do the job for me on his
unix machine?
Stefan Kahlert, Medizinische Poliklinik der Universitaet Bonn
| Stefan Kahlert                 |
| Phone D49-228-465731           |
| UZS13B at    |
You want to become the hangman?
Fine, here is the rope:
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Date: Tue, 13 Sep 1994 07:45:40 +0059 (EDT)
From: Ram Balaraman <synapsys at>
Subject: Multi-Functional CAT & Luciferase Reporter Gene Vectors
To: j.grimbergen at, schupp at,
        umm500 at
Message-Id: <Pine.3.89.9409130711.B58-0100000 at>
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Near Zero-Background Multifunctional Reporter Gene Vectors For Rapid
Analysis of Eukaryotic Promoters & Enhancers.
 The vectors , SV40-Syncat, Syncat I, Syncat II,  SV40-pFlash,
pFlash I and pFlash II, are as their names suggest  CAT & Luciferase
(Luc) reporter gene vectors. What distinguishes  them from other vectors
in this category is that these vectors produce  near-zero background.
This feature is due to the fact, that they use a  modified SV40-t-intron
as the donor for the poly-adenylation signal.  The wild type
SV40-t-intron is the generic donor for this function  and is widely used
in a variety of reporter gene vectors, eg. pCAT- basic, pCAT-promoter,
pGL-basic and pGL-promoter (Promega).  However one little known fact
about the wild-type-t-intron is that it  contains cryptic enhancer
sequences that produce significant  background activity, thereby raising
the threshold of sensitivity.
Until now this feature was not a serious limitation since scientists'
were analysing strong promoters/enhancers that produced high  signal to
noise ratios. However the focus in the past couple of  years has shifted to
(a) the analysis of weak promoters,
(b) promoters  that have very low basal transcription rates but are
specifically  induced to high levels by cytokines,
------- OR -------
(c)  promoters that function only  in cells that are very poorly transfectable.
Analysis of such  regulatory elements requires systems of high sensitivity
as well as  specificity.
The Syncat & pFlash series of vectors provide precisely these capabilities,
since they contain a t-intron polyA signal that has  been modified to be
devoid of cryptic enhancer activity.
The 2nd. feature of these vectors is the choice of the  heterologous promoter
in Syncat II and pFlash II. These vectors use  the well characterized HSV-tk
TATA box containing minimal  promoter situated immediately upstream of
the reporter gene. The  HSV-tk is a widely used basal promoter that has
been documented  to produce no spurious interactions with enhancers of interest
By  contrast vectors like pCAT-promoter or pGL-promoter use the
SV40  promoter. The SV40 promoter contains an atypical TATA-box and  more
seriously has been documented to spuriously repress certain  cytokine
inducible enhancers (Benech, J.Exp.Med. 1992,  Vol. 176:
1115-1123). This latter anomalous property of the SV40 promoter is a
serious liability since it is impossible to be 100% confident that the
cis-elements under analysis will not be spuriously repressed by the SV40
heterologous promoter used in the pCAT/pGL vectors.
Other features of these vectors include a very  versatile multiple cloning
site upstream and downstream of the  reporter gene cassette, flanked by
T3 & T7 promoter sequences for  direct sequencing and creation of
unidirectionally deleted mutant  libraries as well as f1 origin of
replication for ssDNA recovery and  site-directed mutagenesis.
The combination of these features enables you to perform all your DNA
manipulations from--eg., cloning of a 5 kb  genomic 5U flanking region
upstream of the reporter gene ---to---  creation of nested deletion mutant
libraries followed by sequence  verification ---to--- ssDNA-site-directed
mutagenesis and  transfection of each construct --- ALL IN THE SAME
REPORTER  GENE VECTOR YOU STARTED WITH. The time savings alone can be upto
THE FRONT RUNNER & the runner up.
These vectors are available from SynapSys Corp. To  get more info
about these vectors send E-mail to :-
synapsys at
phone & fax # to enable us to mail/fax you any information or otherwise
assist you.
Ram Balaraman
Marketing & Sales
SynapSys Corp. -----We Bridge the Gap-----
7, Bradford Rd., Burlington, MA 01813

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