Effect of multiple freeze-thaw cycles on the stability of positive anti-treponemal
            serum samples

Castejon, Márcia Jorge; Yamashiro, Rosemeire; Oliveira, Elaine L; Silveira, Edilene P. R.; Oliveira, Camila Cardoso de

doi:10.5935/1676-2444.20170038

Cited by 8 publications

(8 citation statements)

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“…Although each study applied a different F/T methodology and targeted different antigens, they all concluded that there was no clinically or statistically significant difference in the antibody levels after several F/T cycles. Interestingly, another study has shown that 174 F/T cycles on anti-treponemal sera did not affect the stability, the reactivity of antibodies, or the samples’ quality when tested by a chemiluminescence assay [1]. The data generated from our study and the previous studies provide concrete knowledge regarding antibody stability in serum, which allows the maximum potential use of serum, especially for those that have undergone multiple F/T cycles.…”

Section: Discussionmentioning

confidence: 60%

“…Serum banks are well established as they are considered to be an essential reference for clinical information and research use. However, there are concerns regarding the effect of repeated freeze-thaw (F/T) cycles on the biological entities of serum proteins, including immunoglobulins (Ig) [1][2][3][4]. It is suspected that repeated F/T cycles may lead to denaturation or degradation of the antibody of interest [5].…”

Section: Introductionmentioning

confidence: 99%

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Effect of multiple freeze–thaw cycles on the detection of anti-SARS-CoV-2 IgG antibodies

Shurrab

Al-Sadeq

Amanullah

et al. 2021

Journal of Medical Microbiology

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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; 95 % 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.

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Section: Discussionmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Effect of multiple freeze–thaw cycles on the detection of anti-SARS-CoV-2 IgG antibodies

Shurrab

Al-Sadeq

Amanullah

et al. 2021

Journal of Medical Microbiology

View full text Add to dashboard Cite

show abstract

“…Although each study applied a different freeze-thaw methodology and targeted different antigens, they all concluded that there was no clinically or statistically significant difference in the antibody levels after several F/T cycles. Interestingly, another study has shown that 174 F/T cycles on anti-treponemal sera did not affect the stability, the reactivity of antibodies, nor the samples’ quality when tested by a chemiluminescence assay (1). The data generated from our study and the previous studies provide concrete knowledge regarding antibody stability in serum, which allows the maximum potential use of serum, especially for those that have undergone multiple F/T cycles.…”

Section: Discussionmentioning

confidence: 99%

“…Serum banks are well-established as they are considered an essential reference for clinical information and research use. However, there are concerns regarding the effect of repeated freeze-thaw (F/T) cycles on the biological entities of serum proteins, including immunoglobulins (Ig) (1-4). It is suspected that repeated F/T cycles may lead to denaturation or degradation of the antibody of interest (5).…”

Section: Introductionmentioning

confidence: 99%

Effect of multiple freeze-thaw cycles on detection of anti-SARS-CoV-2 IgG antibodies

Shurrab

Al-Sadeq

Amanullah

et al. 2021

Preprint

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Several studies have investigated the effect of repeated freeze-thaw (F/T) cycles on RNA detection for SARS-CoV-2. However, no data is 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 one negative SARS-CoV-2 IgG sera from 11 participants, in replicates of five were subjected to a total of 16 F/T cycles and stored at 4 degrees celsius until tested by ELISA. Statistical analysis was done to test for F/T cycle effect. Non-of the 10 positive sera turned into 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; 95% 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 the SARS-CoV-2 IgG antibodies.

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“…In turn, it can suppress proteins and can permanently change the structural properties of complex macromolecules and change their stability [ 29 ]. However, Castejon et al [ 30 ] reported that neither change in the reactivity characteristic of anti-treponemal antibodies in the weak reactive serum nor the absence of expressive effect on the results of the analyzed samples had occurred.…”

Section: V2 Lb Liquid Mediummentioning

confidence: 99%

Freeze-thaw system for thermostable β-Galactosidase isolation from Gedong Songo Geobacillus sp. isolate

2020

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The effective isolation of intracellular enzymes from thermophilic bacteria is challenging because of their sturdy membrane. On the other hand, the low-cost and nontoxic method is essential for industrial food enzymes. The freeze-thaw cycles using acetone-dry ice as a frozen system was studied for efficient isolation of thermostable b-galactosidase from Geobacillus sp. dYTae-14. This enzyme has been known for application in the dairy industry to reduce the lactose content. In this study, the freeze-thaw method was performed with cycle variations 3, 5, and 7 cycles. Acetone-dry ice (-78°C) is used as a frozen system and boiling water for thawing. The b-galactosidase activity was assayed using ortho-Nitrophenyl-β-galactoside (ONPG) as substrate and protein content determined with the Lowry method. The results show that the most effective freeze-thaw is five cycles. The enzyme’s highest specific activity is 3610.13 units/mg proteins at 40-60 % ammonium sulfate saturation, with a purity value of 2.52.

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Effect of multiple freeze-thaw cycles on the stability of positive anti-treponemal serum samples

Cited by 8 publications

References 0 publications

Effect of multiple freeze–thaw cycles on the detection of anti-SARS-CoV-2 IgG antibodies

Effect of multiple freeze–thaw cycles on the detection of anti-SARS-CoV-2 IgG antibodies

Effect of multiple freeze-thaw cycles on detection of anti-SARS-CoV-2 IgG antibodies

Freeze-thaw system for thermostable β-Galactosidase isolation from Gedong Songo Geobacillus sp. isolate

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