Factors that may influence optimal loading concentration include, but are not limited to:

Average insert size.

Number of functional molecules within the library, which means inserts with an adapter at each end.

Quality of the library, for example, no contaminating short fragments.

Accurate quantitation of the library; qPCR is ideal.

Note

PCR favors the amplification of shorter fragments over longer ones in a complex mixture of different length templates. This differential amplification needs to be taken into consideration to maximize sequencing yield. For example, if your library size range contains a large number of shorter fragments, which can yield extremely bright clusters, consider a lower loading concentration or perform additional size selection, where possible.

To help you determine your loading schedule, see the Loading Concentration Calculator at https://techwriting.singulargenomics.com/calculator/Loading-Conc-Calc/Content/Topics/Calculators/Loading-Concentration-Calculator.htm