Lentivirus Titer p24 ELISA Kit

Key Features

Wide Linear Range
Fewer dilutions with linear range From 31.25 to 2,000 pg/ml

Short Assay Time
The complete titration can be finished within 3 hours

High Assay Precision
With Intra-assay CV ≤ 10% and Inter-assay CV ≤ 15%

12 x 8-well Strips
Flexible format, only use the amount as it’s needed

Product List

Learn more about Lentivirus Titer p24 ELISA kit

• Assay Principal

  Lentivirus Titer p24 ELISA kit utilizes two HIV-1 p24 monoclonal antibodies which bind to different epitopes of the p24 protein.

  When standards or samples are added to the capture plate, The p24 proteins in the testing sample can be captured on the plate coated with the HIV-1 p24 capture antibody. Then the HIV-1 p24 detection antibody conjugated with biotin is added to interact with the p24 protein bound on the plate. Streptavidin-Horseradish Peroxidase conjugate (Streptavidin-HRP) is added to interact with the biotin conjugated anti-p24 antibody (Biotin Anti-p24 Antibody). After washing steps, 3,3',5,5'-Tetramethylbenzidine solution (TMB Solution) is added resulting in formation of blue color. The reaction is stopped by adding Stop Solution. Application of the Stop Solution results in the color changing from blue to yellow. The intensity of the color can be read at 450 nm by a microplate reader.

  The concentration of p24 protein in the testing sample is precisely quantified against a p24 standard curve. Then p24 concentration are correlated to the lentivirus titer of cell culture supernatants.

  

  Figure 1: Schematic diagram of Lentivirus Titer p24 ELISA Kit

Validation Data

• High Recovery Rate

  Recovery is a fundamental biophysical characteristic to evaluate immunoassay. Ideally, the recovery rate should be ultimately close to 100%. 100% recovery means there is no interference from the diluent or matrix in the assay. Normally, an 80% to 120% recovery rate can be regarded as there being relatively slight interference from the diluent or matrix. From the assay in triplicates, the recovery rates of GenScript Lentivirus Titer p24 ELISA kit are all located in the range of 80% to 120%, which indicates lentivirus titration with this ELISA kit is accurate and reproducible.

  Table 1: Recovery rate of Lentivirus Titer p24 ELSIA kit in triplicates

  Batch No.	Repeats	Average Conc. pg/mL	Recovery Rate
  			GenScript	Standard(80%-120%)
  #1	3	1945.30	86%	Qualified
  #2	3	1787.64	108%	Qualified
  #3	3	1752.76	90%	Qualified

• High Intra-assay and Inter-assay Precision

  A. High intra-assay precision

  The following are examples of reports and data generated from a representative intra-assay precision validation using the Lentivirus Titer ELISA Kit (Cat. No. L00938, GenScript) for samples at low, medium, and high concentration levels. For testing, each sample was repeated 10 times, and the mean (M) and standard deviation (SD) of the 10 measured concentration results were calculated for each sample, and the coefficient of variation (CV) was calculated. Based on the evaluation results, the intra-assay % CVs are less than 10%, indicating good repeatability of lentivirus titration using the kit.

  Table 2: Intra-assay CV evaluation with three-batch Lentivirus Titer p24 ELISA Kit

  Batch No.	Repeats	Average Conc. pg/mL	%CV
  			GenScript	Standard (≤10%)
  #1	10	215.55	3%	Qualified
  #1	10	829.45	4%	Qualified
  #1	10	1537.42	4%	Qualified
  #2	10	209.60	5%	Qualified
  #2	10	792.76	2%	Qualified
  #2	10	1431.42	3%	Qualified
  #3	10	188.09	6%	Qualified
  #3	10	759.99	4%	Qualified
  #3	10	1377.71	3%	Qualified

  B. High inter-assay precision

  The following are examples of reports and data generated from a representative inter-assay precision validation using 3 different batches of the Lentivirus Titer ELISA Kit (Cat. No. L00938, GenScript) for the samples at low, medium, and high. Each sample was tested for 10 replicates using the kit from three different batches, and the mean (M) and standard deviation (SD) of the 30 measured concentration results were calculated for each sample, and the coefficient of variation (CV) was calculated as well. Based on the results, the Inter-assay % CVs are less than 15%, indicating the kit has good inter-assay precision.

  Table 3: Inter-assay CV evaluation with three-batch Lentivirus Titer p24 ELISA Kit

  Batch Amount	Repeats	Average Conc. pg/mL	%CV
  			GenScript	Standard (≤15%)
  3	3x10	204.41	7%	Qualified
  3	3x10	794.07	5%	Qualified
  3	3x10	1448.85	6%	Qualified

• Lentivirus Titration during Lentivirus Purification and Production

  Utilizing p24 ELISA kit for lentivirus titration during lentivirus purification and production can greatly benefit lentivirus purification process control and optimization. The outstanding characteristics of GenScript Lentivirus Titer p24 ELISA kit that outshines the competitors are its extremely wide linear range from 31.25 to 2,000 pg/ml and short incubation time. With the advantage of a wide linear range, fewer dilutions of the sample would be needed to get the sample titer into the linear range. Much fewer errors that might be caused by dilution can be avoided.

  Table 4a: Lentivirus titration during lentivirus purification and production using GenScript Lentivirus Titer p24 ELISA Kit

  Process	OD Value	Testing p24 Conc.(pg/mL)	Dilution Factor	Actual p24 Conc. (LP/mL)	CV %
  Supernatant	3.151	2445.918	100	Not Valid	/
  	1.225	444.343	3000	1.67E+10
  Nucleic Acid Removal	3.12	2369.055	100	Not Valid	/
  	1.242	451.997	3000	1.69E+10
  Centrifugation	3.103	2328.92	100	Not Valid	/
  	0.94	321.172	3000	1.20E+10
  Clarification and Filtration	3.136	2405.64	100	Not Valid	/
  	0.926	315.765	3000	1.18E+10
  Ultrafiltration and Diafiltration	2.183	1040.264	3000	3.90E+10	3
  	0.152	36.234	90000	4.08E+10
  Clarification and Filtration	1.994	890.168	3000	3.34E+10	6
  	0.142	32.441	90000	3.65E+10
  Gel Filtration	1.496	578.496	3000	2.17E+10	/
  	0.106	18.902	90000	Not Valid
  Ultrafiltration and Diafiltration	2.623	1501.37	3000	5.63E+10	3
  	0.185	47.906	90000	5.39E+10
  Final Product	3.155	2459.286	3000	Not Valid	/
  	0.799	265.916	90000	2.99E+11

  Table 4b: Lentivirus titration during lentivirus purification and production using p24 ELISA Kit from other vendor

  Process	OD Value	Testing p24 Conc.(pg/mL)	Dilution Factor	Actual p24 Conc. (LP/mL)	CV %
  Supernatant	86.687	1.223	12000	1.30E+10	/
  	291.899	3.143	2000	Not Valid
  Nucleic Acid Removal	100.254	1.375	12000	1.50E+10	/
  	282.872	3.073	2000	Not Valid
  Centrifugation	73.79	1.073	12000	1.11E+10	/
  	275.974	3.019	2000	Not Valid
  Clarification and Filtration	69.953	1.028	12000	1.05E+10	/
  	279.996	3.051	2000	Not Valid
  Ultrafiltration and Diafiltration	234.108	2.675	10000	Not Valid	/
  	39.453	0.653	60000	2.96E+10
  Clarification and Filtration	212.127	2.484	10000	Not Valid	/
  	36.317	0.612	60000	2.72E+10
  Gel Filtration	165.17	2.048	10000	2.06E+10	5
  	29.342	0.522	60000	2.20E+10
  Ultrafiltration and Diafiltration	275.001	3.011	10000	Not Valid	/
  	69.346	1.021	60000	5.20E+10
  Final Product	38.46	0.64	480000	2.31E+11	/
  	244.786	2.765	80000	Not Valid

  *The data highlighted in red were out of the linear range of the ELISA kit used.

  During the process development for the lentivirus purification, 18 samples from 9 processes were collected and titrated. The experimental results found that:
  1. The dilution factor of GenScript Lentivirus Titer p24 ELISA Kit is lower than that of the competing p24 Detection Kit.
  2. In the process of diluting the lentivirus into the linear range of p24 ELISA kits, the success rate of 18 samples using the GenScript Lentivirus Titer p24 ELISA Kit with only one dilution was 67%, while the success rate was 56% when using the competing p24 ELISA kit.

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