The radiochemical concentration and the molar concentration have a direct linear relationship. The radioactive and molar concentration may dictate which formulation you need to purchase. Molar concentration (µM) - the total concentration (in moles) of both the labeled and unlabeled product per unit volume.Radioactive concentration, also known as radiochemical concentration (mCi/mL or ♜i/mL) - the total amount of radioactivity per unit volume.There are two ways of expressing concentration when dealing with radioactivity. View a brief explanation of how specific activity is handled for radionuclides and for radiolabeled compounds.Ĭoncentration refers to the amount of material (solute) dissolved in a given volume of liquid (solvent). The closer the specific activity of 33P-gamma-ATP (which has only one possible labeling position) is to the theoretical maximum specific activity for 33P, the greater the proportion of nucleotide molecules that are labeled with the radioisotope. For example, the theoretical maximum specific activity for 33P is ~5000 Ci/mmol. This is the specific activity if 100% of the molecules contain one isotopic label. Theoretical maximum specific activity - Each radioisotope has a maximum theoretical specific activity, often measured in Ci/mmol of the radioactive atom.Specific activity can be changed by adding more "cold" (unlabeled) compound (in this case, unlabeled ATP). These units indicate that there are 3000 Curies per millimole of ATP. For example, 33P-gamma-ATP in the image below has a specific activity of 3000 Ci/mmol on the calibration date. Specific activity (SA) - the amount of radiolabeled mass in a sample, often expressed as Ci/mmol or Ci/mg.The specific activity is one of the key factors used to determine which product to use for your detection method and to obtain optimal assay performance. The term is most often used as a microCurie (♜i). 1 Ci = 3.7×10 10 disintegrations per second = 2.22×10 12 disintegrations per minute (dpm). Curie or Ci - the most common unit of measure for the radioactivity of a substance.Half life - the time it takes for a product to decay sufficiently to convert half of its mass to a stable form.Radioactive material decays until only stable substance is left and the decay of a substance is fixed and measurable. Radioactive decay - the process by which an unstable isotope emits energy to reach a more stable state (Entropy).
Molarity of a carrier-free radionuclideĭownload our free app for iPhone, iPad, or Apple computers.Molarity of material (labeled and unlabeled combined).Volume calculations for radiolabeled compounds.Specific activity and radioactive concentration on the date of use.
iPad, iPhone, Apple app for radiochemical calculations.