What sample volume should be loaded on the QIAsymphony instrument for extraction of 2 ml and 4 ml samples?
FAQ ID - 3701

At least 2.4 ml sample for the 2 ml protocol or 4.5 ml for the 4 ml protocol should be loaded.

Loading smaller volumes increases the risk of “unclear” flagged samples. As described in the corresponding labware list, volumes of 1.4–2.4 ml and 3.5–4.5 ml, respectively, will be processed but flagged “unclear” (“Enable less sample” mode).

Loading volumes less than recommended increases the risk that samples are not transferred (“invalid” flagging). If the sample volume is insufficient, add PBS to the required sample volume before loading the sample.

 When using FIX labware (instrument does not perform liquid-level detection and reporting), load at least 2.1 ml for the 2 ml protocol and at least 4.1 ml for the 4 ml protocol. Because the instrument does not detect sample volumes using FIX labware,  insufficient volumes might result in bubble formation during sample transfer and/or the subsequent binding step. If the sample volume is insufficient, add PBS to the required sample volume before loading the sample.