FAQ: Can coverage be improved for the recent variants?

Yes, spike-in primers have been designed and tested to address low coverage areas caused by KP and JN variants. These primers can be provided free of charge upon request. Please contact info@neb.com. Alternatively, the sequences below can be used for custom primer synthesis from your preferred oligo provider. These spike-in primers should be used with the VarSkip Short v2 primers following the protocols below.
 

VSSv2f Spike-in Mix

Primer

Sequence

Target Concentration in 1xPool (µM)

1

varskip-0317-1_1_LEFT_ALT3

ATCTCTTGTAGATCTGTTCTCTAAACG

0.5

1

varskip-0317-1_05_RIGHT_ALT2

GACAATTTCACAAGCACAGGTTGAG

0.5

1

varskip-0317-1_07_LEFT_ALT2

CCTCTAAAAGCCCCAAAAGAAATTATC

0.5

1

varskip-0317-1_09_RIGHT_ALT2

GTTTACTTTCAGTTATAAATGGCTTAACTTC

0.5

1

varskip-0317-1_11_LEFT_ALT2

GTGGCACTACTGAAATGCTAGC

0.5

1

varskip-0317-1_13_RIGHT_ALT2

TTCATAAGAAAGTGTGCCCATGTAC

0.5

1

varskip-0317-1_15_RIGHT_ALT1

GCTCCAAAGACAACGTATACACC

0.5

1

varskip-0317-1_35_LEFT_ALT2

GATGATTATTTCAATAAAAAGGACTGGTATG

0.5

1

varskip-0317-1_45_RIGHT_ALT2

ATTGATCTCCAGGCGGTGGTTT

0.5

1

49_R_ALT2

GTAATAAGAACACCATTACGGGCAT

0.5

1

varskip-0317-1_53_RIGHT_ALT2

TGAGGATCTGAAAACTTTGTCAGG

0.5

1

55_L_ALT1

CCTACTTATTGTTAATAACGCTACTAATGTT

0.5

1

varskip-0317-1_57_LEFT_ALT6

CTCTGCTTTACTAATGTCTATGCAGA

0.5

2

varskip-0317-1_24_LEFT_ALT2

GCCTTTAATACTTTACTATTCCTTATGTC

0.5

2

varskip-0317-1_28_RIGHT_ALT2

AGGCCAAAGTAACAAGTACAAAAATAGC

0.5

2

varskip-0317-1_32_RIGHT_ALT2

CTGTTATTGCCTGACCAGTACC

0.5

2

varskip-0317-1_34_RIGHT_ALT2

ATCACAGAATTGTACTGTTTTTAACAAAGC

0.5

2

varskip-0317-1_54_RIGHT_ALT2

CTTCAAGGTCCATAAGAAAAGGCT

0.5

2

56L_ALT1

TTATTATGTGGGTTATCTTCAACCTAGG

0.5

2

varskip-0317-1_56_RIGHT_ALT2

CAGCCTGTAAAATCATCTGGTAATTTAT

0.5

 
Protocols for use of spike-in primers:

For 96-reaction kits:

  • Thaw VSSv2f Spike-in Mix 1, VSSv2f Spike-in Mix 2, VSSv2 Primer Mix 1. and VSSv2 Primer Mix 2.
  • Mix and quick spin all four tubes.
  • Add 3 μl of VSSv2f Spike-in Mix 1 to VSSv2 Primer Mix 1, vortex, spin-down, place on ice.
  • Add 2.5 μl of VSSv2f Spike-in Mix 2 to VSSv2 Primer Mix 2, vortex, spin-down, place on ice.
  • Use spiked VarSkip Short v2 Primer Mix 1 and 2 for RT-PCR protocol.

For 24-reaction kits:

  • Thaw VSSv2f Spike-in Mix 1, VSSv2f Spike-in Mix 2, VSSv2 Primer Mix 1. and VSSv2 Primer Mix 2.
  • Mix and quick spin all four tubes.
  • Add 2 μl of VSSv2f Spike-in Mix 1 to 2 μl 0.1x TE to make a ½ dilution of the VSSv2f Spike-in Mix 1.
  • Add 1.5 μl of diluted VSSv2f Spike-in Mix 1 to VSSv2 Primer Mix 1, vortex, spin-down, place on ice.
  • Add 2 μl of VSSv2f Spike-in Mix 2 to 2 μl 0.1x TE to make a ½ dilution of the VSSv2f Spike-in Mix 2.
  • Add 1.25 μl of diluted VSSv2f Spike-in Mix 2 to VSSv2 Primer Mix 2, vortex, spin-down, place on ice.
  • Use spiked VarSkip Short v2 Primer Mix 1 and 2 for RT-PCR protocol.