Human Thymine DNA Glycosylase (TDG) ELISA Kit

Principle of the Assay

The microtiter plate provided in this kit has been pre-coated with an antibody specific to TDG. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific to TDG. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After the TMB substrate solution is added, only those wells that contain TDG, biotin-conjugated antibody, and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of sulphuric acid solution, and the color change is measured spectrophotometrically at a wavelength of 450nm ± 10nm. The concentration of TDG in the samples is then determined by comparing the O.D. of the samples to the standard curve.

For Use with serum, plasma, and cell culture supernatants. For Research Use Only. Not for use in diagnostic procedures.

Target Information

DNA glycosylase that plays a key role in active DNA demethylation: specifically recognizes and binds 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) in the context of CpG sites and mediates their excision through base-excision repair (BER) to install an unmethylated cytosine. Cannot remove 5-hydroxymethylcytosine (5hmC). According to an alternative model, involved in DNA demethylation by mediating DNA glycolase activity toward 5-hydroxymethyluracil (5hmU) produced by deamination of 5hmC. Also involved in DNA repair by acting as a thymine-DNA glycosylase that mediates correction of G/T mispairs to G/C pairs: in the DNA of higher eukaryotes, hydrolytic deamination of 5-methylcytosine to thymine leads to the formation of G/T mismatches. Its role in the repair of canonical base damage is however minor compared to its role in DNA demethylation. It is capable of hydrolyzing the carbon-nitrogen bond between the sugar-phosphate backbone of the DNA and a mispaired thymine. In addition to the G/T, it can remove thymine also from C/T and T/T mispairs in the order G/T >> C/T > T/T. It has no detectable activity on apyrimidinic sites and does not catalyze the removal of thymine from A/T pairs or from single-stranded DNA. It can also remove uracil and 5-bromouracil from mispairs with guanine.

GENE ID	6996
SWISS PROT	Q13569
SYNONYMS	G/T Mismatch-Specific Thymine DNA Glycosylase; Thymine-DNA glycosylase

Materials Supplied

Kit Components	96 Wells Quantity/Size
Pre-coated, ready-to-use 96-well strip plate	1 plate
Plate sealer for 96 wells	2
Standard	2 tubes
Diluent buffer	1 bottle
Detection Reagent A	1 bottle
Detection Reagent B	1 bottle
TMB Substrate	1 tube
Stop Solution	1 tube
Wash Buffer (30 ℅ concentrate)	1 tube
Product data sheet	1 copy

Storage

The TMB Substrate, Wash Buffer (30X concentrate), and the Stop Solution should be stored at 4°C upon receipt, while the other items should be stored at -20°C.

Performance Characteristics

REPEATABILITY	Intra-assay Precision (Precision within an assay): 3 samples with low, middle, and high-level TDG were tested 20 times on one plate, respectively. Inter-assay Precision (Precision between assays): 3 samples with low, middle, and high-level TDG were tested on 3 different plates, with 8 replicates in each plate. CV(%) = SD/meanX100 Intra-Assay: CV<10% Inter-Assay: CV<12%
SENSITIVITY	The minimum detectable dose was 0.038ng/mL.
ASSAY RANGE	0.312-20ng/mL
SPECIFICITY	This assay has high sensitivity and excellent specificity for the detection of TDG. No significant cross-reactivity or interference between TDG and analogs was observed. Note: Limited by current skills and knowledge, it is impossible to perform all possible cross-reactivity detection tests between TDG and all analogs, therefore, cross reactivity may still exist.