A novel approach for high-level expression and purification of GST-fused highly thermostable Taq DNA polymerase in Escherichia coli.

Polymerases are enzymes that synthesize long chains or polymers of nucleic acids, including DNA or RNA of nucleotides. They assemble to copy the template nucleic acids DNA or RNA strand using the base-pairing interactions. One of the polymerase enzyme, Taq DNA polymerase, originally isolated from Thermus aquaticus (Taq) is an enzyme widely used in molecular biology so far. The properties of thermostable enzymes has contributed majorly to specificity, automation, and efficacy of the polymerase chain reaction (PCR), making it a powerful tool for molecular biology research today throughout the world.

Purification of Taq DNA polymerase from the original host results in low yields, labor and time consumption. Therefore, much research has been done before to get this enzyme using an alternative host. So far, all of the existing methodology is more laborious, time consuming and requires a heavy cost. We use a new approach to purifying the enzyme with relatively high efficiency, yield and minimum time consumption using Escherichia coli (E. coli) as an alternative host. We cloned 2500 base pairs of DNA Taq polymerase gene into pGEX-4T-1 vector containing GST-tag, downstream of tac promoter and expressed using isopropyl β-D-1-thiogalactopyranoside (IPTG) as an inducer

The enzyme was purified using chromatography efficient new approach and use in routine PCR tests in our laboratory. Our findings suggest a new approach to facilitate the availability of polymerases for molecular and diagnostic studies. In the future, may be used for purification of other recombinant peptides or proteins used in structural biology and proteomics research-based.

 A novel approach for high-level expression and purification of GST-fused highly thermostable Taq DNA polymerase in Escherichia coli.
A novel approach for high-level expression and purification of GST-fused highly thermostable Taq DNA polymerase in Escherichia coli.

Outside Chelation: EDTA binds Closely Taq DNA Polymerase, Mutt and dUTPase and direct Inhibiting Activity dNTPase.

EDTA is commonly used as a metal ion chelator efficient enzyme cofactor. It is highly soluble, optically inactive and do not interfere with most chemicals used in making standard buffer EDTA common options for generating metal-free conditions for biochemical and biophysical investigations. However, controversy in the literature about the activity of the metal-free enzyme is achieved by using EDTA or otherwise called our attention to the alleged effects of external EDTA chelation. Here, we show that EDTA compete for sites of hydrolases dUTPase nucleotide nucleotide binding by developing a network of interactions within the active site similar to the substrate. To reach these findings, we apply the kinetics and molecular docking technique uses two different dUTPases.

Furthermore, we directly measured the binding of EDTA to dUTPases and two other dNTPases, Taq polymerase and Mutt using isothermal titration calorimetry. EDTA binds proven exothermic and enthalpy driven primarily by submicromolar dissociation constant is much lower than with an enzyme: substrate or Mg: EDTA complex. Control of protein, including ATPase, do not interact with EDTA. Our findings indicate that EDTA can act as a selective inhibitor of the enzyme hydrolysis of dNTPs and urges a rethinking of the use of EDTA in enzymatic trial.

Taq DNA Polymerase, 5 units/µl

ABP-PP-ERTQ200 200U Ask for price

Taq DNA Polymerase, 5 units/µl

ABP-PP-ERTQ500 500U Ask for price

3G HotStart Taq DNA Polymerase (5u/ul)

3GHST81 5x500U
EUR 896.24

Taq DNA Polymerase (High Purity), 5u/ul

HTD0078 5X200U
EUR 129.6

Taq DNA Polymerase (Mg2+ plus Buffer)

P101-01 1000 U
EUR 145.2

Taq DNA Polymerase (Mg2+ plus Buffer)

P101-02 5000 U
EUR 231.6

Taq DNA Polymerase (Mg2+ plus Buffer)

P101-03 10000 U
EUR 314.4

Taq DNA Polymerase (Mg2+ free Buffer)

P102-01 1000 U
EUR 145.2

Taq DNA Polymerase (Mg2+ free Buffer)

P102-02 5000 U
EUR 231.6

Taq DNA Polymerase (Mg2+ free Buffer)

P102-03 10000 U
EUR 314.4

HotStart Taq DNA Polymerase (Mg2+ Plus Buffer)

RK20601 25 U Ask for price

Taq DNA Polymerase

BA00103 500U
EUR 104.4
Description: High quality Taq polymerase for different PCR variations and downstream applications.

Taq DNA Polymerase

BA00104 1000U
EUR 147.6
Description: High quality Taq polymerase for different PCR variations and downstream applications.

Taq DNA Polymerase

BA00105 2500U
EUR 278.4
Description: High quality Taq polymerase for different PCR variations and downstream applications.

Taq DNA polymerase

BT10101 500U
EUR 96
Description: High quality Taq polymerase for different PCR variations and downstream applications.

Taq DNA polymerase

BT10102 1000U
EUR 130.8
Description: High quality Taq polymerase for different PCR variations and downstream applications.

Taq DNA polymerase

BT10103 2000U
EUR 200.4
Description: High quality Taq polymerase for different PCR variations and downstream applications.

Taq DNA Polymerase

L7051001 1000 unit
EUR 234
Description: Premade ready to use kits will always come in handy. Get your experiment done right form the first try by using a validated kit with perfectly balanced reagents proportions and compatibility and by following a clear protocol.

Taq DNA Polymerase

L7051200 200 unit
EUR 104.4
Description: Premade ready to use kits will always come in handy. Get your experiment done right form the first try by using a validated kit with perfectly balanced reagents proportions and compatibility and by following a clear protocol.

Taq DNA Polymerase

9001-2500 each
EUR 614.4

Taq DNA Polymerase

9001-500 each
EUR 229.2

Pfu DNA Polymerase, 5u/ul

B0093(D0090P) 500U
EUR 164.4

T4 DNA Polymerase, 5u/ul

BEP0061 100U
EUR 153.97

Tsg DNA Polymerase, 5u/ul

D0081 5X200U
EUR 112.2

Taq DNA Polymerase (Mg2+ plus Buffer, with dNTP)

P101-d1 1000 U
EUR 163.2

Taq DNA Polymerase (Mg2+ plus Buffer, with dNTP)

P101-d2 5000 U
EUR 320.4

Taq DNA Polymerase (Mg2+ plus Buffer, with dNTP)

P101-d3 10000 U
EUR 490.8

Taq DNA Polymerase (Mg2+ free Buffer, with dNTP)

P102-d1 1000 U
EUR 163.2

Taq DNA Polymerase (Mg2+ free Buffer, with dNTP)

P102-d2 5000 U
EUR 320.4

Taq DNA Polymerase (Mg2+ free Buffer, with dNTP)

P102-d3 10000 U
EUR 490.8

6X DNA Loading Buffer (Blue)

99962-1 4x1.5ML
EUR 124.8
Description: Minimum order quantity: 1 unit of 4x1.5ML

Recombinant Taq DNA Polymerase

7-03634 1,000U Ask for price

Recombinant Taq DNA Polymerase

7-03635 3,000U Ask for price

Recombinant Taq DNA Polymerase

7-03636 10,000U Ask for price

Taq DNA polymerase (+dNTPs)

02-001 200U
EUR 183.6
Description: The Taq DNA polymerase (+dNTPs) is available in Europe and for worldwide shipping via Gentaur.

Taq DNA polymerase (+dNTPs)

02-001-5 5×200U
EUR 308.4
Description: The Taq DNA polymerase (+dNTPs) is available in Europe and for worldwide shipping via Gentaur.

Taq DNA polymerase (-dNTPs)

02-011 200U
EUR 168
Description: The Taq DNA polymerase (-dNTPs) is available in Europe and for worldwide shipping via Gentaur.

Taq DNA polymerase (-dNTPs)

02-011-5 5×200U
EUR 261.6
Description: The Taq DNA polymerase (-dNTPs) is available in Europe and for worldwide shipping via Gentaur.

Taq DNA Polymerase (Recombinant)

abx073521-10000U 10000 U
EUR 710.4

Taq DNA Polymerase (Recombinant)

abx073521-1000U 1000 U
EUR 276

Taq DNA Polymerase (Recombinant)

abx073521-3000U 3000 U
EUR 393.6

Taq DNA Polymerase (500U)

9K-001-0001 500U
EUR 209.29

Taq DNA Polymerase (3000U)

9K-001-0002 3000U
EUR 582

Taq DNA Polymerase (6000U)

9K-001-0033 6000U
EUR 1234.5

Taq DNA Polymerase (1000U)

9K-001-0035 1000U
EUR 418.62

Champagne Taq DNA Polymerase

P122-d1 500 U (2.5 U/μl)
EUR 212.4

Champagne Taq DNA Polymerase

P122-d2 500 U (5 U/μl)
EUR 212.4

Champagne Taq DNA Polymerase

P122-d3 500 U (10 U/μl)
EUR 212.4

Hotstart Taq DNA Polymerase

L7052001 1000 units
EUR 681.6
Description: Premade ready to use kits will always come in handy. Get your experiment done right form the first try by using a validated kit with perfectly balanced reagents proportions and compatibility and by following a clear protocol.

Hotstart Taq DNA Polymerase

L7052250 250 units
EUR 234
Description: Premade ready to use kits will always come in handy. Get your experiment done right form the first try by using a validated kit with perfectly balanced reagents proportions and compatibility and by following a clear protocol.

Taq DNA Polymerase (PCR)

G008 5000 U (1.0 ml)
EUR 246

Taq DNA Polymerase (PCR)

G009 1000 U (200 ul)
EUR 104.4

Taq DNA Polymerase (PCR)

G126 10000 U (2 x 1.0 ml)
EUR 370.8

Taq Plus DNA Polymerase

P201-01 250 U
EUR 147.6

Taq Plus DNA Polymerase

P201-02 1000 U
EUR 213.6

Taq Plus DNA Polymerase

P201-03 3000 U
EUR 382.8

Maximo Taq DNA Polymerase

S101 500 units
EUR 55.2

Maximo Taq DNA Polymerase

S102 5x500 units
EUR 128.4

Maximo Taq DNA Polymerase

S103 20x500 units
EUR 393.6

Taq DNA Polymerase, 5units/㎕

T2200-050 500units
EUR 157.2

Taq DNA Polymerase, 5units/㎕

T2200-100 2x500 units
EUR 230.4

Taq DNA Polymerase, 5units/㎕

T2200-200 4x500 units
EUR 375.6

Recombinant Taq Dna Polymerase

27079804 EACH
EUR 99.18

Recombinant Taq Dna Polymerase

27079806 EACH
EUR 539.22

Maximo Blue-Taq DNA Polymerase (ready-to-load, conc. 1u/µl)

S111 500 units
EUR 63.6

Maximo Blue-Taq DNA Polymerase (ready-to-load, conc. 1u/µl)

S112 5x500 units
EUR 148.8

Maximo Blue-Taq DNA Polymerase (ready-to-load, conc. 1u/µl)

S128 20x500 units
EUR 487.2

Maximo Blue-Taq DNA Polymerase (ready-to-load, conc. 1u/µl)

S129 100x500 units or as bulk
EUR 2142

Recombinant Taq Plus DNA Polymerase

7-03631 250U Ask for price

Recombinant Taq Plus DNA Polymerase

7-03632 750U Ask for price

Recombinant Taq Plus DNA Polymerase

7-03633 2,500U Ask for price

Taq DNA Polymerase - 5,000 units

3245 1/EA
EUR 620.4

Anti-Taq DNA Polymerase Antibody

48369-100ul 100ul
EUR 399.6

Anti-Taq DNA Polymerase Antibody

48369-50ul 50ul
EUR 286.8

Taq Plus DNA Polymerase (Recombinant)

abx073522-2500U 2.500 U
EUR 710.4

Taq Plus DNA Polymerase (Recombinant)

abx073522-250U 250 U
EUR 276

Taq Plus DNA Polymerase (Recombinant)

abx073522-750U 750 U
EUR 393.6

Fast-Taq DNA Polymerase (500U)

9K-001-0036 500U
EUR 420.65

Taq Plus DNA Polymerase (PCR)

G012 250 U (50 ul)
EUR 87.6

Taq Plus DNA Polymerase (PCR)

G040 1000 U (200 ul)
EUR 127.2

YEA taq DNA Polymerase wiodNTP

FYT011-500U 500U Ask for price

Genorise® Taq DNA Polymerase

GR108007 200 tests
EUR 276

Recombinant (E.Coli) Taq DNA Polymerase

RP-394 1000 IU
EUR 196.8

Taq DNA Polymerase Polyclonal Antibody

7018-100 each
EUR 424.8

Taq DNA Polymerase Polyclonal Antibody

7018-30T each
EUR 175.2

ACTaq? Taq DNA Polymerase, 1000U

E2100-1000U each
EUR 260.4

ACTaq? Taq DNA Polymerase, 250U

E2100-250U each
EUR 122.4

6X Loading Buffer

L0501-005 5X1ml
EUR 92.4

6X Loading Buffer

L0502-005 5X1ml
EUR 92.4

Taq DNA polymerase (TQ21) , DNA Aptamer, Biotinylated

AD-146-B Custom Ask for price

Taq DNA polymerase (TQ21) , DNA Aptamer, unlabeled

AD-146-U Custom Ask for price

amfiXpand Taq DNA Ploymerase Buffer*(2X)

P0332-001 1ml
EUR 121.2

Cheetah Hot Start Taq DNA Polymerase

29050 500EU
EUR 355.2
Description: Minimum order quantity: 1 unit of 500EU

Anti-Taq DNA Polymerase Conjugated Antibody

C48369 100ul
EUR 476.4

amfiSure Hot-Start Taq DNA Polymerase

P0322-010 100 units
EUR 176.4

amfiSure Hot-Start Taq DNA Polymerase

P0322-025 250 units
EUR 273.6

YEA taq DNA Polymerase wi dNTP

FYT001-500U 500U Ask for price

Taq DNA Polymerase, 5units/㎕ , Bulk Packing

T2200-B01 10,000 units
EUR 1388.4

Taq DNA Polymerase, 5units/㎕ , Bulk Packing

T2200-B05 5x10,000 units
EUR 6540

HiQTM Taq Red DNA Polymerase, 1unit/㎕

T2201-050 500units
EUR 157.2

HiQTM Taq Red DNA Polymerase, 1unit/㎕

T2201-100 2x500 units
EUR 230.4

HiQTM Taq Red DNA Polymerase, 1unit/㎕

T2201-200 4x500 units
EUR 375.6

Recombinant (E.Coli) Taq Plus DNA Polymerase

RP-395 250 U
EUR 196.8

ACTaq? Taq Blue DNA Polymerase, 1000U

E2100B-1000U each
EUR 272.4

ACTaq? Taq Blue DNA Polymerase, 250U

E2100B-250U each
EUR 126

Taq DNA polymerase (TQ21) , DNA Aptamer, FITC labeled

AD-146-F Custom Ask for price

Maximo DFS-Plus Taq DNA Polymerase DNA-free

N140 500 units
EUR 60

Maximo DFS-Plus Taq DNA Polymerase DNA-free

N142 5x500 units
EUR 144

Maximo DFS-Plus Taq DNA Polymerase DNA-free

N144 20x500 units
EUR 440.4

6x Protein Loading Buffer

abx098124-5ml 5 ml
EUR 226.8

10x Taq Buffer

BA00151 1.8ml
EUR 66
Description: High purity buffer for various PCR applications.

Taq DNA Polymerase 2x Premix - 500 Reactions

3249 1/EA
EUR 228

Taq DNA Polymerase with dNTP Mix (6000U)

9K-001-0018 6000U
EUR 1536.74

Taq DNA Polymerase with dNTP Mix (500U)

9K-001-0031 500U
EUR 351.28

Taq DNA Polymerase with dNTP Mix (3000U)

9K-001-0032 3000U
EUR 1088.87

Taq DNA Polymerase with dNTP Mix (1000U)

9K-001-0034 1000U
EUR 518.84

amfiXpand Taq DNA Polymerase,Including dNTP&MgCl2

P0330-010 100 units
EUR 180

amfiXpand Taq DNA Polymerase,Including dNTP&MgCl3

P0330-020 2x100 units
EUR 286.8

amfiXpand Taq DNA Polymerase,Including dNTP&MgCl2

P0330-050 5X100 units
EUR 465.6

amfiXpand Taq DNA Polymerase,Including dNTP&MgCl2

P0330-250 25X100 units
EUR 2004

amfiXpand Taq DNA Polymerase,Including dNTP&MgCl2

P0330-500 50X100 units
EUR 3591.6

DNA Loading (6X) Buffer for Agarose and Acrylamide Gels

306-205 5x1 ml
EUR 56.4

Accuris Taq Polymerase

PR1000-1000 1 PC
EUR 207.19

Accuris Taq Polymerase

PR1000-500 1 PC
EUR 159.35

Accuris Taq Polymerase

PR1000-6000 1 PC
EUR 742.16

Accuris Taq Polymerase

PR1000-S 1 PC
EUR 83.75

Tsg PlusDNA Polymerase, 5u/ul

D0088 200U
EUR 94.8

Genorise® CLT Taq DNA Polymerase (1000 U)

GR108003 1000 U
EUR 238.8

Taq DNA Polymerase, Ultra Pure, 5 units/ul

T2016-001 1000 units
EUR 198

Taq DNA Polymerase, Ultra Pure, 5 units/ul

T2016-005 5000 units
EUR 360

Taq DNA Polymerase, Ultra Pure, 5 units/ul

T2016-010 10,000 units
EUR 699.6

Taq DNA Polymerase, Ultra Pure, 5 units/ul

T2016-100 100,000 units
EUR 3462

HiQTM Taq Red DNA Polymerase, 1unit/㎕ , Bulk Packing

T2201-B01 10,000 units
EUR 1388.4

HiQTM Taq Red DNA Polymerase, 1unit/㎕ , Bulk Packing

T2201-B05 5x10,000 units
EUR 6540

10x Taq Buffer (MgCl2)

PCRB16 4x1.5ml, 6ml
EUR 70.44

DFS-"HOT" Taq DNA Polymerase (DNA-free sensitive, E-coli. DNA Free)

N150 500 units
EUR 122.4

DFS-"HOT" Taq DNA Polymerase (DNA-free sensitive, E-coli. DNA Free)

N152 5x500 units
EUR 472.8

DFS-"HOT" Taq DNA Polymerase (DNA-free sensitive, E-coli. DNA Free)

N154 20x500 units
EUR 1830

Vazyme LAmp DNA Polymerase (Mg2+ plus buffer)

P301-01 125 U
EUR 145.2

Vazyme LAmp DNA Polymerase (Mg2+ plus buffer)

P301-02 500 U
EUR 210

T4 DNA Ligase, 5u/ul

B1122 1KU
EUR 190.5

T4 DNA Ligase, 5u/ul

B1125 200U
EUR 93.41

EZ Taq Polymerase (HotStart)

9K-005-0020 500U
EUR 245.83

SDS-PAGE Sample Loading Buffer (6x)

abx090649-5ml 5 ml
EUR 243.6

1.2ML Triple Dye Loading Buffer (6X)

NAT1192 1.2ML
EUR 29.75

Taq DNA Polymerase - 5,000 units with separate dNTP Mix

3245d 1/EA
EUR 802.8

Fast-Taq DNA Polymerase with 10mM dNTP Mix (500U)

9K-001-0003 500U
EUR 575.22

Fast-Taq DNA Polymerase with 10mM dNTP Mix (2500U)

9K-001-0004 2500U
EUR 2465.38

High-Taq DNA Polymerase with 10mM dNTP Mix (250U)

9K-001-0005 250U
EUR 384.17

High-Taq DNA Polymerase with 10mM dNTP Mix (4x250U)

9K-001-0006 4x250U
EUR 1055.98

High-Taq DNA Polymerase with 10mM dNTP Mix (5000U)

9K-001-0020 5000U
EUR 2878.8

amfiSure Taq DNA Polymerase, 1unit/ul, Including dNTP&MgCl2

P0310-025 250 unit
EUR 200.4

amfiSure Taq DNA Polymerase, 1unit/ul, Including dNTP&MgCl2

P0310-050 2X250 unit
EUR 300

amfiSure Taq DNA Polymerase, 1unit/ul, Including dNTP&MgCl2

P0310-100 4X250 Unit
EUR 505.2

amfiSure Taq DNA Polymerase, 1unit/ul, Including dNTP&MgCl2

P0310-250 10X250 Unit
EUR 886.8

amfiEco Taq Reaction Buffer(2X)

P0703-001 1ml
EUR 100.8

amfiEco Taq Reaction Buffer(2X)

P0703-005 5ml
EUR 213.6

10x Taq Buffer (NH4)2SO4

PCRB55 4x1.5ml, 6ml
EUR 70.44

amfiEco Taq DNA Polymerase, 1 unit/ul,Including dNTP&MgCl2

P0701-050 500 units
EUR 198

amfiEco Taq DNA Polymerase, 1 unit/ul,Including dNTP&MgCl2

P0701-102 25x500 units
EUR 1712.4

amfiEco Taq DNA Polymerase, 1 unit/ul,Including dNTP&MgCl2

P0701-500 10X500 units
EUR 886.8

Maximo Taq DNA Polymerase (2X pre-mix, ready-to-use)

S113 2x100 rcs
EUR 79.2

Maximo Taq DNA Polymerase (2X pre-mix, ready-to-use)

S114 10x100 rcs
EUR 231.6

Maximo H-SPlus Taq DNA Polymerase (for Hot-Start PCR)

S400 200 units
EUR 86.4

Maximo H-SPlus Taq DNA Polymerase (for Hot-Start PCR)

S410 1000 units
EUR 231.6

DNA Polymerase

ABF5235 100 ug
EUR 525.6

DNA Polymerase

ABD3082 100 ug
EUR 525.6

Vazyme LAmp DNA Polymerase (Mg2+ plus buffer, with dNTP)

P301-d1 125 U
EUR 147.6

Vazyme LAmp DNA Polymerase (Mg2+ plus buffer, with dNTP)

P301-d2 500 U
EUR 213.6

Vazyme LAmp DNA Polymerase (Mg2+ free buffer, with dNTP)

P302-d1 125 U
EUR 147.6

Vazyme LAmp DNA Polymerase (Mg2+ free buffer, with dNTP)

P302-d2 500 U
EUR 213.6

Hot Start Taq DNA Polymerase - 1000 units with seperate dNTP mix

3293d 1/EA
EUR 428.4

amfiSure ONE Taq DNA Polymerase, 1unit/ul, MgCl2 and dNTP Included

P7002-500 500 units
EUR 262.8

amfiSure ONE Taq DNA Polymerase, 1unit/ul, MgCl2 and dNTP Included

P7002-502 2x500 units
EUR 424.8

amfiSure ONE Taq DNA Polymerase, 1unit/ul, MgCl2 and dNTP Included

P7002-510 10x500 units
EUR 1647.6

amfiSure ONE Taq DNA Polymerase, 1unit/ul, MgCl2 and dNTP Included

P7002-525 25x500 units
EUR 3624

amfiSure ONE Taq DNA Polymerase, 1unit/ul, MgCl2 and dNTP Included

P7002-550 50x500 units
EUR 6459.6

T4 DNA Ligase with PEG, 5u/ul

B1442 1KU
EUR 195.72

T4 DNA Ligase with PEG, 5u/ul

B1445 200U
EUR 96.54

Fast DNA Ligation Kit (5u/ul, T4)

BS511 10prep
EUR 85.06

Fast DNA Ligation Kit (5u/ul, T4)

BS512 50prep
EUR 159.18

DNA Loading Buffer

abx098143-5ml 5 ml
EUR 210

DNA Precipitation Buffer

D106 55 ml
EUR 210
Description: DNA Precipitation Buffer by Cygnus Technologies is available in Europe via Gentaur.

utiDNA Polymerase w/ dNTPs

FYT007-500U 500 Units Ask for price

6X GelRed Prestain Buffer with Blue Tracking Dyes

41009 1mL
EUR 160.8
Description: Minimum order quantity: 1 unit of 1mL

Taq DNA Ligase - 10,000 units

3219 1/EA
EUR 303.6

GelRed Prestain Plus 6X DNA Loading Dye

41011 1mL
EUR 176.4
Description: Minimum order quantity: 1 unit of 1mL

DNA polymerase ? (Rat)

10-101 20ug
EUR 465.6
Description: The DNA polymerase ? (Rat) is available in Europe and for worldwide shipping via Gentaur.

DNA polymerase ? (Rat)

10-102 100ug
EUR 1107.6
Description: The DNA polymerase ? (Rat) is available in Europe and for worldwide shipping via Gentaur.

HotTaq DNA Polymerase

BA00203 500U
EUR 174
Description: High quality HotTaq polymerase for different PCR variations and downstream applications.


In order to develop a test to identify the genes responsible for antibiotic resistance in gram-negative bacteria, it has been found that the standard of Taq DNA polymerase (not DNA-free) blaTEM contaminated with fragments of genes that varied in length and number. BlaTEM complete gene sequences are absent or detected in very small amounts. We developed an approach to avoid false-positive findings caused by contamination polymerase gene sequence in a conventional blaTEM