Options from Mirus Bio
Label IT® reagents are available in several formats, which provides researchers with a variety of options for their nucleic acid labeling experiments. In this Tip, we cover the difference between the four formats of Label IT® kits and provide guidance on which to choose for a given application.
The four formats of Label IT® kits are:
(1) Label IT® Nucleic Acid Labeling Kits
(2) Label IT® Tracker™ Intracellular Nucleic Acid Localization Kits
(3) Label IT® siRNA Tracker™ Intracellular Localization Kits
(4) Label IT® Nucleic Acid Modifying Kits
The table below summarizes key features of each kit format. NOTE: the Label IT® reagent (µl):nucleic acid (µg) ratio (v:w) listed in the table is the recommended starting value prescribed in each kit’s respective protocol. Using this starting ratio in a standard Label IT® labeling reaction (37°C, 1 hour incubation), one can expect to achieve the labeling density listed in the table below. Importantly, the labeling density can easily be adjusted by adjusting the ratio and/or the reaction time. Please reference the Tips from the Bench: Adjust Labeling Density Using Label IT® Reagents page for more information on this topic.
The
Label IT® Tracker™ and siRNA Tracker™ kits are optimized labeling kits for
in vitro and
in vivo tracking of plasmid and siRNA, respectively. That is, using each kit’s respective protocol will result in a labeling density that does not interfere with gene expression and knockdown studies. Because the labeling density can be easily adjusted with slight protocol modifications, the resultant labeling density may not be the key consideration when choosing a
Label IT® kit.
Instead, one might choose to use the
Label IT® Nucleic Acid Labeling or Modifying kits if the fluorophore or label of interest is unavailable for the Tracker™ formats. In addition to Cy®3, Cy®5, fluorescein, CX-Rhodamine, TM-Rhodamine and biotin reagents, the
Label IT® Nucleic Acid Labeling Kits are also available with MFP488, digoxin and DNP reagents. The
Label IT® Nucleic Acid Modifying Kits include the
Label IT® Amine Reagent, which attaches amine functional groups to nucleic acids; once labeled, nucleic acids can be further coupled to NH2 reactive substrates or chemicals.
Lastly, the
Label IT® Nucleic Acid Labeling and Modifying kits include a few extra components compared to the Tracker™ kits: Denaturation Reagent D1, Neutralization Buffer N1 and G50 microspin purification columns. The Denaturation Reagent D1 and Neutralization Buffer N1 are primarily used for hybridization experiments (see Page 6 of the
Label IT® Nucleic Acid Labeling Kit Full Protocol). The G50 microspin purification columns are used to purify labeled nucleic acids from excess
Label IT® reagents after the
Label IT® reaction. Purification can also be easily performed with ethanol precipitation, which is described step-by-step in the protocols for all
Label IT® kits and the Tips from the Bench:
Post-labeling Purification of Nucleic Acids with the Label IT® Reagents page.
In conclusion, we recommend using the
Label IT® Tracker™ and siRNA Tracker™ kits for performing standard gene expression and knockdown studies. We recommend using the
Label IT® Nucleic Acid Labeling and Modifying kits if requiring a fluorophore or label that is unavailable in the Tracker™ formats and/or if the extra components (Denaturation Reagent D1, Neutralization Buffer N1 and G50 microspin purification columns) are required.
Still unsure of which
Label IT® kit to use? Try out the Decision Tree below or contact
techsupport@mirusbio.com for guidance.