Isolate Plasma

This step uses the ML STAR to isolate plasma from whole blood specimens.

• Hamilton Robotics 1000 µl tip rack
• Deep-well plates (2)

Make sure to use the correct plate type for the Intermediate Plasma and Final Plasma plates. Use of a deep-well reservoir instead of a deep-well plate leads to sample amalgamation and can produce incorrect results.

1. Label 1 deep-well plate Intermediate Plasma and apply a barcode.
2. Label 1 deep-well plate Final Plasma and apply a barcode.
3. For 24, 48, and 96 sample batches, load a full rack of the individually counted 8-channel tips (for tracks 49–54) before starting the method.
4. Add 2 ml of DPBS to 20 ml Illumina Reagent Tub.
1. Open the AppLauncher, and then select VeriSeq NIPT Method.
2. Enter a unique Batch ID and user name, and then select OK.

Batch ID can contain ≤ 26 characters. You can use numbers, letters, underscores (_), or dashes (-). For example: 2025-10-16_Batch3.

The Batch ID is not case-sensitive. Case-sensitive Batch IDs are not considered unique.

Batch names must be unique and must not differ only in capitalization. For example, batch names Batch01 and batch01 are not unique. This same rule applies for Sample ID naming.

3. Select New Batch.
4. After initiation, select OK to begin plasma isolation.
5. Select the batch size, and then select OK.
6. Select the number of no template controls (NTCs), and then select OK.

NTC slots are always the last slots selected. For example, with two NTCs in a 24-sample run, positions 23 and 24 are NTCs.

7. Perform one of the following steps:
• To load an existing sample sheet, select the sample sheet associated with the batch, and then select OK.
• To proceed without selecting a sample sheet, select No Sample Sheet.

For information on creating a sample sheet, refer to the Software Overview section.

If you choose No Sample Sheet, make sure you set the default sample values in the Workflow Manager Service Tools. For more information, refer to the Software Overview section.

8. Confirm that all barcodes are affixed, and then load the samples, tips, and plates (barcode-facing right) onto the carrier.
9. Select OK after each load prompt.

Sample Batch Size

Carrier

Type

Track

Item

Site Position

24, 48, 96

Tip

7–12

1000 µl tips

5

1000 µl tips (96 batch only)

4, 5

Tube

15

Prepared blood sample tubes 1–24 (for all batch sizes)

1–24

Tube

16

Prepared blood sample tubes 25–48 (48 and 96 batch size only)

25–48

Tube

17

Prepared blood sample tubes 49–72 (96 batch size only)

49–72

Tube

18

Prepared blood sample tubes 73–96 (96 batch size only)

73–96

Multiflex

19–24

Empty deep-well plate, Final Plasma – barcoded

4

Multiflex

19–24

Empty deep-well plate, Intermediate Plasma – barcoded

5

Reagent

47

[Optional] Dulbecco's Phosphate-Buffered Saline (DPBS) - used for no template control (NTC)

5
10. Make sure that the carriers, labware, and reagents are loaded correctly.
11. On the Pre-Spin Deck Verification screen, select OK.
12. Observe the ML STAR perform the automated steps.
13. When prompted by the Workflow Manager, make sure the ML STAR loading deck is free of any obstructions to allow the ML STAR to unload the carriers.
14. Select Unload to unload the deck.
15. Remove the Intermediate Plasma deep-well plate as follows.
a. Inspect the plate for consistent volumes in each well (no pipette errors). The expected volume is 1000 µl.
b. Record any inconsistencies when the Plasma Isolation procedure is complete.
c. Seal the plate, load with balance, and centrifuge at 5600 × g for 10 minutes with the brake off or on the lowest setting.
16. Select Yes to proceed to final Plasma Preparation.
17. Remove the plate seal and reload the plate onto the carrier.

Sample Batch Size

Carrier

Type

Track

Item

Site Position

24, 48, 96

Multiflex

19–24

Intermediate Plasma deep-well plate

5
18. Select the Intermediate Plasma plate has been spun checkbox, and then select OK.
19. Observe the ML STAR perform the automated steps.
20. When prompted by the Workflow Manager, make sure that the ML STAR loading deck is free of any obstructions to allow the ML STAR to unload the carriers.
21. Select Unload to unload the deck.
22. When prompted by the Workflow Manager, empty the carriers and deck.
23. Remove the Final Plasma deep-well plate.
24. Inspect the plate for the following errors:
• Inconsistent volumes in each well. The expected volume is 900 µl.
• Visible cell pellets.
• Excessive hemolysis.

If you observe abnormal visible cell pellets or excessive hemolysis, invalidate the affected sample at the end of the Plasma Isolation method or use Batch Manager. For more information about Batch Manager, refer to the VeriSeq NIPT Batch Manager section.

25. When prompted by the Workflow Manager, select OK.
26. Enter comments about affected wells, and then select OK.
27. Perform one of the following steps.
• To proceed to cfDNA Extraction, select Yes.
• To stop, select Exit.

SAFE STOPPING POINT

If you are stopping, seal the Final Plasma plate and store at 2°C to 8°C for up to 7 days.