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Method for nucleotide sequence amplification

United States Patent 5,545,539

Miller
 
August 13, 1996
 
Method for nucleotide sequence amplifica
tion 
Abstract
 
This invention relates to an improvement
target nucleotide sequence by using an e
osmolyte in the reaction mixture of an a
found that the use of a glycine-based os
bands in the amplification product allow
nucleotide sequence. For example, detect
sequence, indicative of Huntington's Dis
of a glycine-based osmolyte.
 of the procedure for amplifying a 
ffective amount of a glycine-based 
mplification procedure. It has been 
molyte reduces the appearance of stutter 
ing for easier detection of the target 
ion of the target trinucleotide repeat 
ease, is made clearer with the use 
 
Inventors: Miller; Glenn A. (Hopkinton, 
MA)
Assignee: Genzyme Corporation (Cambridge
, MA)
Appl. No.: 326432
 
Filed: October 18, 1994
 
Current U.S. Class: 435/91.2; 435/91.21;
 435/91.5; 536/22.1; 536/23.1
Intern'l Class: C12P 019/34; C07H 021/00
 
Field of Search: 435/91.2,91.21,91.5 536
/22.1,23.1
References Cited
 
U.S. Patent Documents
 
5192659, Mar. 1993, Simons
 
538602, 4Jan., 1995, Kacian et al.
 
Other References
 
Han, Jian et al. (1994), "Over Represent
and (CGG) repeats in the human genome", 
9 1735-1740. 
ation of the disease associated (CAG) 
Nucleic Acids Research vol. 22, No. 
 
Stallings, Raymond L. (1994), "Distribut
in Different Categories of Mammalian Gen
Barron, Lilias, H. et al. (1994), "A sin
rich sequence immediately 3' to the unst
cDNA shows almost complete disequilibriu
in the Scottish population" Human Molecu
Koide, R. et al. (1994), "Unstable expan
torubral-pallidoluysian atrophy (DRPLA)"
ion of Trinucleotide Microsatellites 
omic . . . " Genomics, 21:116-121. 
gle allele from the polymorphic CCG 
able CAG trinucleotide in the IT15 
m with Huntington's disease chromosomes 
lar Genetics vol. 3, No. 1 173-175. 
sion of CAG repeat in hereditary denta-
, Nature Genetics, 6:9-13. 
Litt, Michael, et al. (1993), "Shadow Ba
leotide Repeats: Some Causes and Cures",
nds Seen When Typing Polymorphic Dinuc-
 Biotechniques, vol. 15:280-284. 
Snell, Russell, G., (1993), "Relationshi
and phenotypic variation in Huntington's
Knight, S. J. L. et al., "Trinucleotide 
ion of a CpG Island in FRAXE Mental Reta
p between trinucleotide repeat expansion 
 disease", Nature Genetics, 4:393-397. 
Repeat Amplification and Hypermethylat-
rdation", Cell, 74:127-134. 
Orr, Harry, T. et al., (1993), "Expansio
repeat in spinocerebellar ataxia type 1"
n of an unstable trinucleotide CAG 
, Nature Genetics, 4:221-226. 
Riess, Olaf, et al., (1993), "Improved P
repeats causing Huntington's disease", H
6, p. 637. 
CR conditions for the stretch of (CAG).sub.n 
uman Molecular Genetics, vol. 2, No. 
 
Goldberg, Paul Y. et al. (1993) "A PCR m
cleotide repeat expansion in Huntington 
vol. 2, No. 6, 635-636. 
ethod for accurate assessment of trinu-
Disease", Human Molecular Genetics, 
 
Valdes, John M. et al. (1993), "A simple
of Huntinton's disease", Human Molecular
The Huntington's Disease Collaborative R
Containing a Trinucleotide Repeat That I
Disease Chromsomes" Cell 72:971-983. 
 non-radioactive method for diagnosis 
 Genetics, vol. 2, No. 6, 633-634. 
esearch Group (1993), "A Novel Gene 
s Expanded and Unstable on Huntington's 
 
Hauge, X. Y. et al. (1993), "A study of 
typing dinucleotide repeat polymorphisms
vol. 2, No. 4, 411-415. 
the orgin of `shadow bands` seen when 
 by the PCR" Human Molecular Genetics, 
 
Rees, William, A. et al. (1993), "Betain
ion Dependence of DNA Melting", Biochemi
e Can Eliminate the Base Pair Composit-
stry, 32:137-144. 
Aslanidis, Charalampos, et al. (1992), "
dystrophy region and mapping of the puta
Buxton, Jessica, et al. (1992), "Detecti
specific to individuals with myotonic dy
Cloning of the essential myotonic 
tive defect", Nature, 355:548-551. 
on of an unstable fragment of DNA 
strophy", Nature, 355:547-548. 
Harley, Helen, G. (1992), "Expansion of 
variation in myotionic dystrophy", Natur
an unstable DNA region and pheno-typic 
e, 355:545-546. 
Fu, Y. H. et al. (1992), "An Unstable Tr
Myotonic Muscular Dystrophy", Science, 2
iplet Repeat in a Gene Related to 
55:1256-1258. 
Andrew, Susan E. (1993), "The relationsh
length and clinical features Huntington 
La Spada, Albert R., et al. (1991), "And
ked spinal and bulbar muscular atrophy",
ip between trinucleotide (CAG) repeat 
disease", Nature Genetics, 4:398-403. 
rogen receptor gene mutations in X-lin-
 Nature, 352:77-79. 
Kremer, E. J., et al. (1991), "Mapping o
to a Trinucleotide Repeat Sequence p(CCG
Verkerk, Annemieke et al. (1991), "Ident
a CGG Repeat Coincident with a Breakpoin
Variation in Fragile X Syndrome", Cell 6
f DNA Instability at the Fragile X 
).sub.n ", Science, 252:1711-1714. 
ification of a Gene (FMR-1) Containing 
t Cluster Region Exhibiting Length 
5:905-914. 
Yu, S. M. et al. (1991), "Fragile X Geno
Region of DNA", Science, 252:1179-1181. 
type Characterized by an Unstable 
 
Miller, S. A. (1988), "A simple salting 
human nucleated cells", vol. 16, No. 3, 
out procedure for extracting DNA from 
p. 1215. 
Hippel, Peter H. et al. (1972), "DNA-Pro
ular Biology and Departments of Chemistr
pp. 231-300. 
tein Interactions", Institute of Molec-
y and Biology, U of Oregon, Eugene, 
 
Melchior, William, B. et al. (1973), "Al
of dA-dT and dG-dC Base Pairs in DNA", P
2, pp. 298-302.
teration of the Relative Stability 
roc.Nat. Acad. Sci. , vol. 70, No. 
 
Primary Examiner: Wityshyn; Michael G. 
 
Assistant Examiner: Prats; Francisco C. 
 
Attorney, Agent or Firm: Salcedo; F. Bra
d 
Claims
 
The invention claimed is: 
 
1. In the procedure for amplifying a tar
trinucleotide repeats, the improvement c
of a trimethylglycine to the reaction mi
procedure wherein fewer amplification pr
the target nucleotide sequence are produ
absence of trimethylglycine. 
get nucleotide sequence containing 
omprising adding an effective amount 
xture of a Taq polymerase chain reaction 
oducts which do not correspond to 
ced than would be produced in the 
 
2. The procedure of claim 1 wherein the 
is indicative of a disease state. 
nucleotide sequence being amplified 
 
3. The procedure of claim 1 wherein the 
4. A kit for amplifying a target nucleot
repeats, comprising in separate containe
target nucleotide sequence is a DNA. 
ide sequence containing trinucleotide 
rs: 
a) the components for a Taq polymerase c
hain reaction; and 
b) a trimethylglycine. 
 
5. The kit of claim 4 wherein the the nu
is indicative of a disease state. 
cleotide sequence being amplified 
 
6. The kit of claim 4 wherein the target
 nucleotide sequence is a DNA.
Description
 
BACKGROUND OF THE INVENTION 
 
Surveys of human genomic DNA have indica
are present in abundance (Stallings, Gen
al., Nucleic Acids Res.,1994. 22(9): p. 
these sequences has fostered their use i
number of human diseases have been shown
a subset of these repetitive sequences, 
1993, 72(6): p. 971-83; Fu et al., Scien
et al., Cell, 1993, 74(1): p. 127-34; Or
221-6; Harley et al., Nature, 1992, 355(
1992, 355(6360): p. 547-8; Aslanidis et 
La-Spada et al., Nature, 1991. 352(6330)
1991, 338(8762): p. 289-92; Yu et al., S
Kremer et al., Science, 1991. 252(5013):
1991, 65(5): p. 905-14; Koide et al., Na
ted that tandemly reiterated sequences 
omics, 1994. 21: p. 116-21; Han et 
1735-40). The polymorphic nature of 
n a variety of studies. Recently a 
 to be caused by the expansion of 
trinucleotide repeats (HDCRG, Cell, 
ce, 1992. 255(5049): p. 1256-8; Knight 
r et al., Nat Genet, 1993, 4(3): p. 
6360): p. 545-6; Buxton et al., Nature, 
al., Nature, 1992, 355(6360): p. 548-51; 
: p. 77-9; Sutherland et al., Lancet, 
cience, 1991, 252(5010): p. 1179-81; 
 p. 1711-4; Verkerk et al., Cell, 
t Genet, 1994, 6(1): p. 9-13). 
All of the currently known diseases caus
by repeats high in dG+dC (guanine and cy
et al., 1994). One method for analyzing 
amplifying the region using the polymera
dG+dC content renders amplification and/
to an increased melting temperature, or 
of the expanded motif. A common result o
repeat motif with a high dG+dC content i
tion products which do not correspond to
Hum. Molec. Genet., 1993, 2(4): p. 411-1
complicates the interpretation of result
have noted the difficulty in interpretin
ton's disease (HD) (Riess, O., et al., H
Goldberg et al., Hum Mol Genet, 1993. 2(
Genet, 1993, 2(6): p. 633-4; Snell et al
Barron et al., Hum. Molec. Genet., 1994,
ed by trinucleotide repeats are caused 
tosine respectively) content (Han 
the expansion of such repeats is by 
se chain reaction (PCR). The high 
or DNA sequencing very difficult due 
T.sub.m, and stable secondary structure 
f amplifying a region containing a 
s the presence of additional amplifica-
 the desired product (Hauge et al., 
5). Such "stutter" or "shadow" banding 
s of an assay. A number of authors 
g the banding patterns seen in Hunting-
um Mol Genet, 1993, 2(6): p. 637; 
6): p. 635-6; Valdes et al., Hum Mol 
., Nat Genet, 1993, 4(4): p. 393-7; 
 3(1): p. 173-175). 
Several theories addressing the problem 
been put forth (Litt et al., Biotech., 1
mechanisms resulting in false banding pa
annealing to a repetitive sequence or st
third explanation proposes that secondar
sequences allow the extending DNA strand
this were to occur during the early cycl
could be made which would eventually app
Secondary structure resulting in additio
ased stability of a region with an incre
stability of base pairs has been a subje
Phosphate binding cations have long been
of the DNA helix (von Hippel et al., Ann
The most likely mechanism for this alter
affect that these cations (Cs.sup.+, Li.
Mg.sup.++, Ca.sup.++) have on the transf
from a non-aqueous to an aqueous environ
cations effectively increase the solubil
which acts to destabilize the helix in a
of "stutter" or "shadow" banding have 
993, 15(2): p. 280-284). Possible 
tterns may include improper primer 
rand slippage during synthesis. A 
y structure unique to the repetitive 
 to skip cassettes of repeats. If 
es of a PCR reaction sufficient template 
ear as additional or "stutter" bands. 
nal banding may be caused by the incre-
ased dG+dC content. The differential 
ct of inquiry for over three decades. 
 known to be general destabilizers 
. Rev. Biochem., 1972, 41: p. 231-300) 
ation of helical stability is the 
sup.+, Na.sup.+, K.sup.+, Rb.sup.+, 
er of free energy of a nucleotide 
ment (von Hippel et al., 1972). These 
ity of nucleotides in aqueous solutions 
 general fashion. 
Another class of compounds has been show
DNA helix based on nucleotide compositio
are known to preferentially bind in DNA 
et al., PNAS, 1973, 70(2): p. 298-302). 
on the differential levels of hydration 
the tetraalkylammonium ion being used. P
base pairs are more highly hydrated than
relatively more suitable binding site fo
ions (Tunis et al., Biopolymers, 1968, 6
demonstrated that larger tetraalkylammon
of DNA while smaller tetraalkylammonium 
effect based on base composition (Melchi
in this case, is to produce a relative i
pairs relative to dG.dC base pairs thus 
ibution to the T.sub.m of a DNA sequence
determining a T.sub.m at which DNA secon
use, however, of tetraalkylammonium comp
their destabilization effect on DNA-prot
tions necessary to achieve DNA isostabil
1993, 32(1): p. 137-44). 
n to alter relative stability of the 
n. Various tetraalkylammonium ions 
grooves at dA.dT base pairs (Melchior 
The mechanism in this case relies 
between base pairs and the size of 
revious work has suggested that dA.dT 
 dG.dC base pairs thus providing a 
r the nonpolar arms of alkylammonium 
: p. 1218-1223). It has also been 
ium ions are general destabilizers 
ions have a differential stabilization 
or et al., 1973). The overall effect, 
sostabilization of the dA.dT base 
eliminating the base composition contr-
. Isostabilization is desirable in 
dary structure would be minimal. The 
ounds in these studies is offset by 
ein interactions at the salt concentra-
ization (Rees et al., Biochemistry, 
 
There is a need for a compound which wou
of the tetraalkylammonium compounds with
effects. 
ld offer the isostabilizing effect 
out the DNA-protein altering side 
 
SUMMARY OF THE INVENTION 
 
This invention relates to an improvement
target nucleotide sequence, by using an 
osmolyte in the reaction mixture of the 
found that the use of a glycine-based os
bands in the amplification product allow
nucleotide sequence. For example, detect
sequence, indicative of Huntington's Dis
of a glycine-based osmolyte. 
 of the procedure for amplifying a 
effective amount of a glycine-based 
amplification procedure. It has been 
molyte reduces the appearance of stutter 
ing for easier detection of the target 
ion of the target trinucleotide repeat 
ease, is made clearer with the use 
 
The present invention further relates to
ide sequence for diagnostic analysis, wh
osmolyte to be used in the amplification
 a kit for amplifying a target nucleot-
erein the kit includes a glycine-based 
 procedure. 
This invention, in addition, relates to 
nucleotide sequence, the improvement com
of a glycine-based osmolyte to the react
DETAILED DESCRIPTION OF THE INVENTION 
the improvement of sequencing a target 
prising adding an effective amount 
ion mixture of an sequencing procedure. 
 
This invention is based upon the discove
is added to a PCR amplification reaction
on's disease the resultant product of th
interpretable. The glycine-based osmolyt
of the tetraalkylammonium compounds with
effects. 
ry that when a glycine-based osmolyte 
 mixture for the detection of Huntingt-
e amplification procedure is more 
e offers the isostabilizing effect 
out its DNA-protein altering side 
 
The term "amplifying" refers to the repe
nucleic acids (DNA) or ribonucleic acids
or non-specific means resulting in an in
DNA or RNA sequences intended to be copi
rase Chain Reaction (PCR), Nucleic Acid 
Transcription-based Amplification System
ation (3SR), Q-beta replicase, Ligation 
Chain Reaction (LCR). 
ated copying of sequences of deoxyribo-
 (RNA) through the use of specific 
crease in the amount of the specific 
ed. These processes include the Polyme-
Sequence Based Amplification (NASBA), 
 (TAS), Self-sustained Sequence Replic-
amplification reaction (LAR) and Ligase 
 
A glycine-based osmolyte suitable for us
trimethylglycine, glycine, sarcosine and
e in the present invention includes 
 dimethylglycine. 
The term "target nucleotide sequence" re
sequence, the presence of which is indic
Such "target nucleotide sequences" would
otide sequence motifs or patterns specif
thereof, nucleotide sequences specific a
sequences of interest for research purpo
tion to a disease. In general, "target n
region of contiguous nucleic acids which
technology. 
fers to a portion of a nucleotide 
ative of a condition, such as a disease. 
 include, but not be limited to, nucle-
ic to a particular disease and causative 
s a marker of a disease, and nucleotide 
ses which may not have a direct connec-
ucleotide sequences" could be any 
 are amenable to an amplification 
 
The term "sequencing" refers to the copy
via biochemical processes. Such "sequenc
the deoxyribonucleic or ribonucleic acid
sequence and the order in which those nu
A typical enzymatic sequencing procedure
of contiguous double stranded nucleic ac
ent single strands, adding a sequencing 
the aforementioned region and through th
synthesizing a complementary stretch of 
as Sanger or dideoxy sequencing, a porti
of the complementary stretch of nucelic 
terminate the extension of a nucleic aci
run each containing one of the four poss
dideoxynucleic acid in a given reaction 
relative to its comparable deoxynucleic 
in the sequence. The result is a series 
depending upon the location at which the
By also incorporating a detection system
or fluorescent, it is possible to determ
in the region in question. 
ing of a target nucleotide sequence 
ing" refers to the determination of 
 composition of a target nucleotide 
cleic acids occur in that sequence. 
 would entail the isolation of a region 
ids, separating them into their compon-
primer homologous to a portion of 
e use of nucleic acid polymerase enzymes 
nucleic acids. In one scheme known 
on of the reagents used in the synthesis 
acids are dideoxynucleic acids which 
d sequence. Four reactions are normally 
ible dideoxynucleic acids. As the 
is present at a low concentration 
acid it is not used at every occurrence 
of extension products of various lengths 
 dideoxynucleic acid was incorporated. 
 of some type, typically radioactive 
ine the sequence of nucleic acids 
 
EXEMPLIFICATION 
 
EXAMPLE 1 
 
Genomic DNA was isolated from peripheral
salt extraction method of Miller et al. 
extracting DNA from human nucleated cell
p. 1215) and resuspended in sterile wate
The PCR primer HD17-F3 (5'-GGC GCA CCT G
Technologies, Inc. of Alameda, Calif.) (
with fluorescein by the incorporation of
synthesis by Operon Technologies. 
 blood mononuclear cells by the high 
(A simple salting out procedure for 
s. Nucleic Acids Res, 1988. 16(3): 
r to a concentration of 1 .mu.g/.mu.l. 
GA AAA GC-3') (purchased from Operon 
Seq. I.D. No.: 1) was 5' end labeled 
 a fluorescein amidite during HD17-F3 
 
Amplification of HD specific sequence wa
and HD17-R1 (5'-GCG GCT GAG GAA GCT GA-3
No.: 2) obtained as HPLC purified stocks
following: 100-500 ng of genomic DNA, PC
KCl, 2 mM MgCl.sub.2) (obtained from Sig
(Pharmacia) to a final concentration of 
was 7-deaza-GTP (Pharmacia), 12.5pM HD17
labelled HD17-F3, 2.5M BETAINE.TM. Mono 
Sigma Chemical), sterile water. Reaction
for three minutes prior to the addition 
from AmpliTaq, Perkin-Elmer of Foster Ci
in a Perkin-Elmer 480 thermal cycler at 
C., 1 min., 74.degree. C., 1 min. for a 
products were analyzed using a 6% sequen
acia A.L.F. automated sequencer. Sizing 
to a M13 sequence ladder run on each gel
by using the Fragment Manager software p
s completed using primers HD17-F3 
') (Operon Technologies) (Seq. ID 
. Each PCR reaction contained the 
R buffer (IOmM Tris, pH 8.4, 5 OmM 
ma Chemical of St. Louis, Mo.), dNTP's 
200 .mu.M (50% of the dGTP content 
-R1, 3.1 pM HD17-F3, 9.4 pM fluorescein 
hydrate (N,N,N, trimethylglycine, 
 tubes were heated to 95.degree. C. 
of 5 units of Taq polymerase (obtained 
ty, Calif.). The reactions were cycled 
95.degree. C., 1 min., 62.degree. 
total of 30 cycles. Amplification 
cing gel containing 8M urea on a Pharm-
of bands was accomplished by comparison 
. Areas under the peaks were determined 
ackage from Pharmacia. 
Comparisons were made to identical DNA s
primers in a PCR reaction mix described 
between trinucleotide (CAG) repeat lengt
disease. Nat Genet, 1993. 4(4): p. 398-4
amples amplified with the identical 
in Andrew, et al. (The relationship 
h and clinical features of Huntington's 
03). 
Table 1 demonstrates the effect BETAINE.
The maximum peak was selected for each l
each peak using the Fragment Manager sof
based on height above a uniform baseline
determined by drawing a line from the na
region to normalize comparison between c
glycine increases the area under the sel
samples amplified without N,N,N trimethy
when analyzing a normal size HD allele a
analyzing HD alleles in the affected ran
TM. has on amplification of HD alleles. 
ane by analysis of the area under 
tware package which selects peaks 
. The baseline for each curve was 
dir of one peak to the next nadir 
urves. The addition of N,N,N trimethyl-
ected peak, as compared to identical 
lglycine, by an average of 9 fold 
nd by an average of 19.5 fold when 
ge. 
    ____________________________________
______________________________________
    Normal Allele    Affected Allele
 
                                 Fold in
crease with
    Area under peak  Area under peak
 
                                 BETAINE
 
    Sample
 
         BETAINE
 
               No Betaine
 
                     BETAINE
 
                           No Betaine
 
                                 Normal
 
                                      Af
fected
    ____________________________________
______________________________________
    1     732.2
 
                45.6 218.2 17.4  16.5 13
 
    2    2207  188.4 890.3 33    12   27
.5
     3*   1519.3/
 
                413.1/           4/4.5*
 
         1212.7
 
               286.8
 
    4    2654.2
 
               322   264.2 15     8.5 18
 
    ____________________________________
______________________________________
     *Sample taken from an individual wi
th two normal alleles. Values indicate
     the area under the peak for each no
with
rmal allele and the fold increase 
 
     BETAINE .TM..
 
EQUIVALENTS 
 
Those skilled in the art will recognize,
more than routine experimentation many e
of the invention described herein. Such 
ssed by the following claims: 
 or be able to ascertain, using no 
quivalents to the specific embodiments 
equivalents are intended to be encompa-