SCLTest, Standard for Curve Verification of Legipid® (Ref. No. 311-10-SC)
SCLTest, Standard for Legipid® Curve Verification (Ref. No. 311-10-SC) is a simple and fast system for the laboratory to verify, if necessary, the calibration curve of the Legipid Legionella®Fast Detection test.
SCLTest allows you to prepare a series of standard samples of 9 mL, at three different levels of Log10CFUeq, with n-replicas for each level. The laboratory records the relative absorbances obtained for each concentration when applying the Legipid® test to the samples.
Reference 311-10-SC contains 5 vials per level (high, medium, low) with a volume of 0.6 mL/vial of a non-cultivable frozen suspension of a known concentration of Log10CFUeq and a bottle of L0 with a volume of 300ml.
Once received, vials should be immediately stored at -20 ± 5°C. The expiration of the material, properly stored, is 3 months from the date of supply. Each set of vials per level is labeled with its batch number and storage conditions. In addition, the protocol includes code, batch number and expiration, so the traceability of all vials is guaranteed.
The curve, provided by the manufacturer, predicts the concentration of equivalent CFUs (CFUeq) in a sample as a function of relative absorbance (Absr) at 429 nm. On a Log10-Log10 scale, it is a linear calibration curve, characterized by its slope and its intercept:
Log10 CFUeq = 2.3061 x Log10 Absr + 4.9815
With the data of the validation of the Legipid® test, the confidence intervals (CI) with a confidence level of 95% are provided, both for the slope and for the intercept of said curve:
- for the slope [1.83, 2.78]
- for the intercept [4.53, 5.43]
The data obtained are entered into a spreadsheet that contrasts the hypothesis that the experimental values of slope and intercept are within their CIs. In that case, the verification is suitable, and the linear calibration curve of the test is accepted.