DTPA

high-resolution terminology - matching measurements at high-resolution

DTPA

Description

[[Description::DTPA (Diethylenetriamine-N,N,N',N,N-pentaacetic acid, pentetic acid,(Carboxymethyl)imino]bis(ethylenenitrilo)-tetra-acetic acid) is a polyaminopolycarboxylic acid (like EDTA) chelator of metal cations. DTPA wraps around a metal ion by forming up to eight bounds, because each COO- group and and N-center serves a center for chelation. With transition metals the number of bounds is less than eight. The compound is not cell membrane permeable. In general, it chelates multivalent ions stronger than EDTA.]]

Abbreviation: DTPA

Application in HRR

Fluorometry:

• In Amplex UltraRed assay systems with HRP, there is a spontaneous increase in the UltoroxRed fluorescence signal over the experimental time without any biological sample. This high background flux can be related to iron contamination. We have done a set of experiments, where we added DTPA as an iron-chelator into the O2k-chamber during AmR measurements. As a matter of fact, DTPA significantly reduced the high chemical background flux in MiR05 without affecting respiration.
• Administration of DTPA into the O2k-chamber is recommended before all other chemicals because the iron chelation of the compound is time-dependent; it takes 10-15 min.
• Experiments may also be run without DTPA.

DTPA (C₂H₂O₂); Dr.Ehrenstorfer GmbH (E 13095000) or Sigma Aldrich (D-1133); CAS 67-43-6; The commercial powder can be stored at room temperature. The stock solution has to be stored at -20 °C; M: 393.35 g·mol^-1

• Solubility: It is soluble in water (4,8 g/l at 25 °C), but not readily soluble in ethanol or apolar solvents.
• Stability constant: see: [1]:

Metal	DTPA	EDTA
Ca(II)	10.74	10.96
Mg(II)	9.3	8.69
Fe(II)	16.5	14.3
Fe(III)	28.6	25.1
Mn(II)	15.6	14.04
Zn(II)	18.75	16.5

Preparation of the 5 mM stock solution of DTPA:

1. Weigh 1.967 mg of DTPA in a 2 mL glass vial.
2. Dissolve in 500 µL H₂O and add 6 µL of 5M KOH to set the pH.
3. Heat up the solution up to 33 °C.
4. Add 2 µL 5 M KOH to adjust the pH ~ 8-9.
5. Add 500 µL H₂O to get 5 mM stock solution.
6. Divide into 50 µL portions in Eppendorf tubes.
7. Store at -20 °C.

»O2k manual titrations: MiPNet09.12 O2k-Titrations

• Final concentration in O2k-chamber: 15 µM
• Stock solution: 5 mM
• Titration volume: 6 µL

MitoPedia methods: Fluorometry