Comparative Analysis between Martin’s Formula and Friedewald’s Formula with Direct Homogenous Assay for Estimating Low Density Lipoprotein Cholesterol Level in Nepalese Population

Background: Low density lipoproteinforms a basis of decision making in treatment of hypercholesterolemic patients and primary target of intervention. Its cost effective and accurate measurementis a need for every clinical laboratories and different calculation methods has been adopted as a replacement to direct assays. This study aims to evaluate the Martin’s formula and Friedewald’s formula in a sample of Nepalese population compared against direct homogenous assay. Materials and Methods: This is a cross-sectional study conducted in Department of Biochemistry from Feb 2020 to January 2021. Serum samples of the participants were analysed for total cholesterol, triglyceride, high density lipoprotein and low density lipoprotein. Martin’s and Friedewald’s formula were applied to get calculated value of low density lipoprotein from both methods. Passing and Bablok regression analysis was used for methods comparison. Results: The mean age of participants was 54.2 ± 8.9 years. Passing-Bablok regression analysis showed Friedewald’s formula performed better than Martin’s formula as per systematic and proportional bias when compared with directassay. However at lowerserum low density lipoprotein level, underestimation of low density lipoprotein compared to direct assay was more common in Friedewald’s formula. At high triglyceride level more percentage error of difference of mean from direct assay was found for Friedewald’s formula. Conclusion: When compared to direct assay, Friedewald’s formula was found to be in better agreement than Martin’s formula. Martin’s formula had advantage over Friedewald’s formula at lower serum low density lipoprotein level and higher triglyceride level where Friedewald’s formula mostly underestimated low density lipoprotein.

Calixarene based portable sensor for the direct assay of indiscriminate ephedrine content of weight loss herbal preparations

Calixarene based solid-state potentiometric sensor for direct assay of indiscriminate ephedrine content in weight loss herbal products.

Viral RNA load quantification as helpful tool to arbitrate SARS–CoV-2 detection results in respiratory samples

Purpose: The increasing COVID-19 widespread has created the necessity to assess the diagnostic accuracy of newly introduced (RT-PCR based) assays for SARS–CoV-2 RNA detection in respiratory tract samples.Methods: We compared the results of the Allplex™ 2019-nCoV assay with those of the Simplexa™ COVID-19 Direct assay, both performed on 125 nasal/oropharyngeal swab samples of patients with COVID-19 suspicion.Results: Fifty-four samples tested positive (CT below 40) and 71 negative (CT above 40) with the Allplex™ 2019-nCoV assay, whereas 47 of 54 samples were also positive with the Simplexa™ COVID-19 Direct assay. Eight results were discordant, resulting in 93.6% agreement between the assays. We used the Quanty COVID-19 assay—developed to detect and quantify SARS–CoV-2 in respiratory tract samples—to arbitrate these results. One Allplex™ 2019-nCoV negative (but Simplexa™ COVID-19 positive) and seven Simplexa™ COVID-19 negative samples were truly false negative. Interestingly, a Spearman’s negative association was found between the viral RNA loads quantified by the Quanty COVID-19 assay and the CT values of RT PCRs performed with either the Allplex™ 2019–nCoV assay or the Simplexa™ COVID-19 Direct assay. However, the strength of this association was higher for the Allplex™ 2019–nCoV assay (N gene, ρ = −0.92; RdRP gene, ρ = −0.91) than for the Simplexa™ COVID-19 Direct assay (ORF1ab gene, ρ = −0.65; S gene, ρ = −0.80).Conclusion: The Allplex™ 2019–nCoV and Simplexa™ COVID-19 Direct assays yielded comparable results. However, the role these assays might play in future clinical practice warrants larger comparison studies.