The calculation of the Degree of Labeling (DoL) of your samples gives a good indication of how well the labeling reaction was carried out.
We highly recommend that it is performed for each labeling reaction. 

Please note:

• Sub-optimal nucleic acid purity can cause a decreased DoL
• Correct determination of the amount of nucleic acid added to the labeling reaction is important to reach the optimal DoL

As a guide optimal DoL values for various applications are given below.

Click here to download an easy-to-use Excel sheet for DoL calculations

NOTE: The DoL value should be the Recommended DoL as indicated in the table. It is advised to use the material for microarray hybridization only when the DoL value is inside the recommended range, i.e. between 1.0-2.5 (for arrayCGH) or 1.0-3.6 (for RNA or cDNA). DoL values lower than 1.0 may not produce enough signal, whereas DoL values higher than 2.5 (aCGH) or 3.6 (RNA or cDNA) might cause either high background levels or quenching of signal. In these cases please refer to the trouble shooting section of the respective manual.

Typical Nanodrop readings of nucleic acids labeled with Cy3-ULS (blue line, Cy3 fluorescence at 550 nm) and Cy5-ULS (red line, Cy5 fluorescence at 650nm) following KREApure removal of unreacted dye. 

The calculation of the Degree of Labeling (DoL) of your samples gives a good indication of how well the labeling reaction was carried out.
We highly recommend that it is performed for each labeling reaction. 

Please note:

• Sub-optimal nucleic acid purity can cause a decreased DoL
• Correct determination of the amount of nucleic acid added to the labeling reaction is important to reach the optimal DoL

As a guide optimal DoL values for various applications are given below.

Click here to download an easy-to-use Excel sheet for DoL calculations

NOTE: The DoL value should be the Recommended DoL as indicated in the table. It is advised to use the material for microarray hybridization only when the DoL value is inside the recommended range, i.e. between 1.0-2.5 (for arrayCGH) or 1.0-3.6 (for RNA or cDNA). DoL values lower than 1.0 may not produce enough signal, whereas DoL values higher than 2.5 (aCGH) or 3.6 (RNA or cDNA) might cause either high background levels or quenching of signal. In these cases please refer to the trouble shooting section of the respective manual.

Typical Nanodrop readings of nucleic acids labeled with Cy3-ULS (blue line, Cy3 fluorescence at 550 nm) and Cy5-ULS (red line, Cy5 fluorescence at 650nm) following KREApure removal of unreacted dye.