The Label IT® Technology allows easy scaling of the labeling reaction without affecting labeling performance. If the final wt./vol. ratio of nucleic acid to Label IT® reagent does not change as a result of the volumetric scale up or down, the labeling densities are not going to get affected.
The total volume of a typical labeling reaction can be varied from as low as 20 µl to as high as 1 ml. It is very important to maintain the final concentration of Labeling Buffer A at 1X in the reaction to avoid inhibition due to high salt concentration.
When the volume of sample nucleic acid is high due to low stock concentration, simply increase the total volume of the labeling reaction up to 1 ml. For the best and most consistent labeling performance, use clean, intact nucleic acid in your labeling reactions. Crude nucleic acid preparations, especially when used in volumes exceeding the protocol recommendations, may compromise the efficiency of labeling reactions. This is due to the presence of contaminants such as salts, bacterial endotoxin, and proteins that affect or compete with the electrostatic interaction between the reagent and nucleic acid.
Label IT® labeling reactions can be scaled down volumetrically to as low as 20 µl. When using lower volumes of nucleic acid than recommended, it is critical to ensure that the amount of Label IT® Reagent does not exceed more than 20% of the total reaction volume.
If the scaling of the labeling reaction affects the final wt./vol. ratio of nucleic acid to Label IT® reagent, the labeling density will be altered. For further details, see Adjust Labeling Density Using Label IT® Reagents.