Effect of multiple freeze-thaw cycles on the detection of anti-SARS-CoV-2 IgG antibodies.
J Med Microbiol
; 70(8)2021 Aug.
Article
in En
| MEDLINE
| ID: mdl-34356000
ABSTRACT
Several studies have investigated the effect of repeated freeze-thaw (F/T) cycles on RNA detection for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, no data are available regarding the effect of repeated F/T cycles on SARS-CoV-2 antibody detection in serum. We investigated the effect of multiple F/T cycles on anti-SARS-CoV-2 IgG detection using an ELISA test targeting the nucleocapsid antibodies. Ten positive and 1 negative SARS-CoV-2 IgG sera from 11 participants, in replicates of 5, were subjected to a total of 16 F/T cycles and stored at 4 °C until tested by ELISA. Statistical analysis was performed to test for F/T cycle effect. None of the 10 positive sera became negative after 16 F/T cycles. There was no significant difference in the OD average reading between the first and last F/T cycles, except for one serum with a minimal decline in the OD. The random effect linear regression of log (OD) on the number of cycles showed no significant trend, with a slope consistent with zero (B=-0.0001; 95â% CI -0.0008; 0.0006; P-value=0.781). These results suggest that multiple F/T cycles had no effect on the ability of the ELISA assay to detect SARS-CoV-2 IgG antibodies.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Blood Preservation
/
Immunoglobulin G
/
Cryopreservation
/
SARS-CoV-2
/
COVID-19
/
Antibodies, Viral
Type of study:
Diagnostic_studies
Limits:
Humans
Language:
En
Journal:
J Med Microbiol
Year:
2021
Document type:
Article
Affiliation country:
Qatar