Fresh 1.0 μL aliquots were used for each replicate measurement. The sample solution was removed between each measurement by wiping the upper and lower sample surfaces with a clean, dry laboratory wipe.
The second study assessed the carryover of a solution of ~20 mg/mL BSA. The measurement sequence was as described above, substituting the BSA for the nucleic acid sample and PBS for dH20.
As seen in Tables 1 and 2, the blank solution measured both before and after the nucleic acid and protein samples were below the DS-11 lower detection limit.
Ultra high concentration protein samples may require more rigorous wiping between samples. A study using a high concentration BSA sample showed a lack of carryover when surfaces were vigorously wiped using a dry lab wipe between BSA measurements. Subsequent PBS measurements met the expected results of being within the +/- 0.1 mg/mL lower detection limit of the instrument.Table 1: dsDNA and BSA Carryover
|Sample (n=5)||Average mg/mL|
The studies demonstrated a lack of significant carryover for either high concentrations of nucleic acid or protein samples. The DS-11 microvolume measurement surface facilitates easy cleanup to ensure minimal-to-no carryover of high concentration samples.
Revised 19 Oct 2020