Having difficulties with your experiment?

We are dedicated to your success. Get back on track. View our expert recommendations for commonly encountered problem scenarios.

View the relevant questions below:


We ship clones as glycerol stocks at –80°C. We recommend making a fresh glycerol stock soon after receipt. Here are some additional suggestions:

  • Verify whether the correct antibiotic was used to grow the clone.
    • Check vector map for antibiotic resistance gene or
    • Check cap color of tube containing the glycerol stock and use the information below to determine which antibiotic to use:
      • Yellow cap: Zeocin
      • Purple cap: chloramphenicol
      • Red cap: carbenicillin or ampicillin
      • Green cap: kanamycin

This may be due to one of the following reasons:

  • Database error – there is a ~12.5% error rate in GenBank for cDNA clones, meaning that the sequence in the GenBank database does not match the sequence of the clone in the indicated well.
  • Incorrect pick in the manufacturing lab – these clones are housed in 96-well (or in the case of BACs, 384-well) plates and human error can occur. If this is the issue, getting a replacement would help. This issue is less likely in case of Ultimate™ ORF clones as these are not stored in plates but in individual tubes.
  • A mixed population in the plate – for the same reason as in #2, these wells can become cross-contaminated. We always recommend analyzing several colonies from any particular culture.

Note: Besides Ultimate™ ORF clones, other clones are not guaranteed to exactly match GenBank sequences and may differ by one or more bases because of allelic and isoform variances.

  • We may have had this clone in the past, but it might have been removed from the collection because it was a “no grow”
  • If it is a recently created clone, it might take us a while to stock it. We only offer clones that have been entered into the NCBI database more than 6 months to 1 year ago.
  • Please check with ATTC ( www.attc.org ) or Open Biosystems (www.openbiosystems.com) to see if they carry the clone .