To begin my words,

I will show my assumption about the oligonucleotide process.

1. Drying process itself doesn't influence to oligonucleotide quantity.

2. The OD value should be same between first and final one.

I measured the optical density (O.D) of primers.

It was 8.5 OD.

We dried it until turning into solid phase.

I resuspended this sample and measured its quantity but a little gap in the value happened.

It comes to 8.9 OD.

After that, I measured it again with new sample.

(That means discard all liquids in microplates, prepare microplate for O.D. reading again and then put the samples in stock to microplate). But it became 6.7 OD.

Simply put,

General information

• There is an sample of oligonucleotide.
• Length : 21mer

First quantification

• ABS : 1.298
• Volume : 160 ul
• OD : 8.5
• Solution : A solution

Drying it

First trial of final quantification

• ABS : 1.355
• The volume of resuspension : 160 ul
• OD : 8.9
• Solution : A solution

Second trial of final quantification with new sample

• ABS : 1.018
• The volume of resuspension : 160 ul
• OD : 6.7

Theoretically,

The quantification (OD) between first and final should be same

since during drying process oligonucleotides doesn't be loss

and I resuspend it with same volume and same solution.

but the OD between first and final was different.

Can I get some advices about this issues?