Understanding Oligo Synthesis Scales and Yields at Ella Biotech

When you order custom DNA or RNA oligonucleotides (oligos) from us, you’ll notice two different measurements using the same units (like nmol or µmol) – the synthesis scale and the final yield. Let us explain these important terms:

What is synthesis scale?

• In oligonucleotide synthesis, „scale“ refers to the starting amount of material used in the synthesis process.
• At Ella Biotech, we typically offer 40 nmol and 200 nmol synthesis scales.
• Think of the synthesis scale as the number of „starting points“ we use to make your DNA/RNA.
• When we specify a „200 nmol scale,“ we’re using a solid material with 200 nmol of attachment sites where DNA chains can begin to grow.
• We use these standardized synthesis scales to ensure consistent production conditions and strict quality control.

Why does the final yield vary?

Yield is the final amount of usable oligo you receive after synthesis and purification. It will be lower than the synthesis scale because:

• Building DNA/RNA is like building a long chain – at each step, some chains aren’t built perfectly.
• The longer your desired sequence or the more modifications you want, the more chances there are for errors.
• For example, if you order 20-base long oligos at the 200 nmol scale, you may get about 100 nmol of usable product after desalting. If you opt for further HPLC purification, the yield will drop to about 50 nmol as the process removes shorter sequences, giving you higher purity oligos.

Your final yield will depend on two main factors:

1. The complexity of your oligo:

• Longer sequences mean more opportunities for error.
• Adding modifications (such as fluorescent labels) will further reduce the yield.
• Sequences that can fold into complex structures are more challenging to purify.

2. The purification method you choose:

• Basic desalting: Provides more material, but contains imperfect sequences.
• HPLC purification: Provides less material but higher quality (only perfect sequences).

At Ella Biotech, we’re committed to being transparent about our synthesis process. We want you to understand exactly what you’re ordering and what you can expect in terms of yield. If you have any questions about synthesis scales or expected yields for your specific oligo, our technical support team is here to help.

The tables below show the estimated yields, which vary depending on the length of the oligo, the modifications, and the optimal purification method chosen.