COVID-19 (SARS-CoV-2) PCR assay


  • Nasal/Throat swabs collected using BD dry swabs/Remel M4RT/Copan 321C UTM or Copan 147C / Citoswab or miraclean swabs.
  • Samples should be taken from symptomatic patients between days 1–5 from onset of symptoms.
  • Specimens should be sent to the laboratory at ambient temperature in Category B packaging and labelled as containing HIGH RISK specimen.
  • For best results, please send samples on the day they are taken. However, samples are stable at ambient temperature for 7 days.

The assay

Infection with SARS-CoV-2, an RNA virus, is diagnosed using reverse-transcriptase real-time PCR. The assays used at TDL show a minimum sensitivity of 98% and a specificity of 100%, with no cross-reactivity with other viruses.


Image: CDC/ Alissa Eckert, MS; Dan Higgins, MAMS


COVID-19 (SARS-CoV-2) antibody testing


  • SST/Serum
    • Capillary self collection can be used for the Roche Elecsys Anti-SARS-CoV-2 S and Roche Elecsys  Anti-SARS-CoV-2 assays.
  • Testing should be undertaken 14 days or more following exposure, onset of symptoms, or post-vaccination.
  • For best results, please send samples on the day they are taken. However, samples are stable at ambient temperature for 7 days.

The assays

TDL offers 4 assays for the detection of antibodies targeted against SARS-CoV-2:

  • Roche Elecsys Anti-SARS-CoV-2 S (Spike) – spike protein, quantitative, total antibodies NEW
  • Roche Elecsys  Anti-SARS-CoV-2 – nucleocapsid (N) protein, qualitiative, total antibodies
  • Abbott Architect SARS-CoV-2 IgG – nucleocapsid protein, qualitiative, IgG antibodies
  • Abbott Architect SARS-CoV-2 IgM – spike protein, qualitiative, IgM antibodies

COVID-19 information

Background overviews of SARS-CoV-2 and COVID-19

  • The virus
  • Transmission
  • Infection and symptoms
  • Clinical characteristics
  • Immune response
  • Variants
  • Testing
  • Sequalae


Read more

COVID-19 Travel Testing

TDL provides 'Fit to Fly', ‘Day 2/Day 8’, and 'Day 5 Test to Release' services.

Read more

SARS-CoV-2 Rapid RNA Sequencing

The Doctors Laboratory is offering a rapid sequencing service for samples previously identified as SARS-CoV-2 positive. This service is avaiable to both NHS and Independent sector laboratories.

Read more

Contact us

To discuss these tests, please contact:

Annette Wilkinson, The Doctors Laboratory, The Halo Building,1 Mabledon Place, London WC1H 9AX

Tel: +44 (0)20 7307 7373  E-mail: 

How TDL is helping the UK’s response to COVID-19

TDL has been testing for COVID-19 since the disease first emerged. The team has developed new detection methods, worked closely with hospitals and with those opening their own labs, and by January 2021 had the capacity to process more than 20,000 PCR tests a day.