Pentachlorophenol ELISA Kit

DBCO-PEG4-Butyraldehyde is a click chemistry PEG reagent containing a terminal butylraldehyde group. Butyraldehyde reacts with hydrazide to form a stable hydrazone linkage or with alkoxyamines to form a stable oxime bond. The hydrophilic PEG spacer arm improves water solubility and provides a long and flexible connection that minimizes steric hindrance involved with ligation. DBCO is commonly used for copper-free Click Chemistry reactions. Reagent grade, for research use only.

DBCO-PEG4-Butyraldehyde is a click chemistry PEG reagent containing a terminal butylraldehyde group. Butyraldehyde reacts with hydrazide to form a stable hydrazone linkage or with alkoxyamines to form a stable oxime bond. The hydrophilic PEG spacer arm improves water solubility and provides a long and flexible connection that minimizes steric hindrance involved with ligation. DBCO is commonly used for copper-free Click Chemistry reactions. Reagent grade, for research use only.

Endonucleases DNA-specific, dsDNase

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Double-Strand Specific dsDNase (dsDNase) is ideal for fast and effective removal of contaminating DNA from PCR master mixes.

Taq polymerases are commonly contaminated by bacterial DNA. This is a problem in PCR based bacterial typing and detection as it might cause false positive results. The unique properties of dsDNase make it suited for removal of contaminating DNA from PCR master mixes prior to addition of DNA template.

In figure 1, a PCR master mix was treated with different amounts of dsDNase before performing a qPCR to measure the contaminating bacterial DNA in the master mix. ArcticZymes dsDNase effectively removed contaminating DNA below known levels of the assay detection limits.

The dsDNase from Arctic shrimp (Pandalus borealis) is recombinantly produced in Pichia pastoris. It cleaves phosphodiester linkages in DNA to yield oligonucleotides with 5’-phosphate and 3’-hydroxyl termini.

The specific activity is estimated to be 30 times higher than that of bovine DNase I. In the presence of magnesium as only divalent cation and using oligos as a substrate, the activity towards dsDNA is 5000-fold higher than towards ssDNA.

The unique double strand-specificity allows specific degradation of dsDNA while leaving shorter ssDNA as primers and probes essentially intact. Easy inactivation by moderate heat (65°C) allows addition of DNA intended for analysis directly after removal of contaminating DNA.

Workflow – Decontamination of PCR master mixes

Recommended applications:

• Decontamination of PCR master mixes
• Removal of genomic DNA from RNA preparations

Key advantages with dsDNase:

• Double-strand DNA specific endonuclease
• High specific activity
• Can be heat-inactivated by moderate heat treatment (65°C for 15 minutes)
• Producing 5′-phospho-oligonucleotide products

Figures

Figure 1. The dsDNase effectively removes contaminated DNA

The dsDNase effectively removes contaminated DNA:

A PCR master mix was preincubated with various concentrations of dsDNase. After treatment, no DNA was amplified in non-template controls.

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Properties

Specificity towards double-stranded DNA

Nucleic acid specificity has been tested towards double- and single-stranded DNA and RNA oligonucleotides. The specificity of dsDNase towards the substrate has been measured using 15-mer oligonucleotides with FAM at 5′ and DarkQuencher® 3′ (Eurogentec). The fluorescence is proportional to enzyme activity. Assay conditions: 25 mM Tris pH 7.5, 5 mM MgCl₂, and 2 μM oligonucleotide.

Relative activities

Substrate                  Relative Activity
dsDNA                           100%
ssDNA                          <0.03%
dsRNA                          <0.01%
ssRNA                           <0.01%

Double-Strand Specific dsDNase (dsDNase) is ideal for fast and effective removal of contaminating DNA from PCR master mixes.

Taq polymerases are commonly contaminated by bacterial DNA. This is a problem in PCR based bacterial typing and detection as it might cause false positive results. The unique properties of dsDNase make it suited for removal of contaminating DNA from PCR master mixes prior to addition of DNA template.

Introduction

Intended Use

For the isolation and differentiation of sorbitol-negative Escherichia coli serotype O157 from food and animal feed and other materials

Principle and Interpretation

Enzymatic digest of casein and enzymatic digest of animal tissue provides nitrogen source, vitamins and growth factors; sodium chloride maintains balanced osmoticpressure; sorbitol is a fermentable sugar; No. 3 bile salt and crystal violet inhibit Gram-positive bacteria, potassiumtellurite inhibits non-o157 Escherichia coli, and cefixime inhibits Proteus; neutral red is a pH indicator; and agar is the coagulant of the culture medium.

Formulation

Ingredients	/liter
Enzymatic digest of casein	17.0g
Enzymatic digest of animal tissue	3.0g
Sorbitol	10.0g
Bile salt No.3	1.5g
Sodium chloride	5.0g
Neutral red	0.03g
Crystal violet	0.001g
Agar	15.0g
pH 7.1±0.2 at 25°C

Preparation

Weigh 51.5g of this product, add 1L of distilled water or deionized water, stir, heat and boil until completely dissolved, dispense into Erlenmeyer flasks, and sterilize at 121℃ for 15min. Melt the sterilized culture medium and cool it to about 45℃, add 1 tube of supporting reagent (SR0240) (0.25mg potassium tellurite and 0.005mg Cefixime) to every 100mL of basal culture medium, mix and pour into the plate.

Quality Control

Cultural characteristics observed after incubation at 35-37°C for 18-24hours

Quality control strains	Growth	Colony color
Escherichia coli ATCC25922	PR≥0.7	pale pink to red
Escherichia coli 0157:H7 NCTC12900	PR≥0.7	colorless
Staphylococcus aureus ATCC 25923	Total inhibition	–

Sorage and Shelf Life

Keep container tightly closed, store in a cool, dry place, away from bright light. Storage period of 3 years.

Precautions

1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort

2. Keep container tightly closed after using to prevent clumping.

Waste Disposal

Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.

Intended Use For the isolation and differentiation of sorbitol-negative Escherichia coli serotype O157 from food and animal feed and other materials Principle and Interpretation Enzymatic ……