Product Comparison: Sensitivity Comparison Between EnSURE & SystemSURE Plus Luminometers
Hygiena provides a range of ATP detection tests and luminometers to help users reach the optimal sensitivity needed for their ATP monitoring programs.
This document compares the Relative Light Unit (RLU) measurements achieved with known dilutions of ATP using UltraSnap (Cat No. US2020) and SuperSnap (Cat No. SUS3000) ATP detection tests measured with EnSURE and SystemSURE Plus luminometers.
Purpose
To compare RLU measurements with differing configurations of Hygiena ATP luminometers using known low levels of ATP.
Procedure Sample Preparation
ATP was diluted in 50mM Tris-Acetate buffer from a certified stock solution (2x10-2 Molar) to a concentration of 2x10-7 Molar. The diluted concentration (2x10-7 Molar) was further diluted to 2x10-8 , 2x10-9 , and 2x10-10 Molar. A 10μl sample was taken from one of the three dilutions and pipetted onto the UltraSnap or Supersnap swab tip, then measured with EnSURE and SystemSURE Plus luminometers. Twenty replicates were made of each test.
Assay Method
UltraSnap or SuperSnap device activity was measured as follows:
- Remove swab from swab tube
- Pipette 10μl of ATP solution directly onto the center of the end of each swab tip
- Replace swab tube and break the Snap-Valve in two directions
- Squeeze reagent reservoir twice to dispense the reagent
- Shake gently to bathe the swab in the reagent for 10 seconds
- Measure activity by inserting the device in to the luminometer
Results
Table 1. Average RLU measurements on EnSURE and SystemSure Plus with known concentrations of ATP using UltraSnap and SuperSnap
| Sample: | 2x10^15 moles ATP (2fmoles) | 2x10^14 moles ATP (20fmoles) | 2x10^13 moles ATP (200fmoles) |
|---|---|---|---|
| System: | UltraSnap (RLU) | ||
| SystemSure Plus | 2 | 21 | 199 |
| EnSURE | 3 | 42 | 400 |
| SuperSnap (RLU) | |||
| SystemSure Plus | 8 | 82 | 718 |
| EnSURE | 16 | 164 | 1436 |
Table 2. RLU measurements from various system configurations. For example, 1 femtomole of ATP measured with UltraSnap and SystemSURE Plus is equivalent to1 RLU. 1 femtomole of ATP measured with SuperSnap and EnSURE is equivalent to 7.2-8 RLU.
| System | UltraSnap | SuperSnap |
|---|---|---|
| SystemSure Plus | 1 | 3.6-4 |
| EnSURE | 2 | 7.2-8 |
Conclusion
Hygiena monitoring systems and ATP swabs detect low levels of ATP, down to a single femtomole. EnSURE RLU results are exactly twice the RLU results on the SystemSURE Plus. Increased sensitivity of the EnSURE system with SuperSnap ATP swabs enable detection that is up to 8 times more sensitive than the SystemSURE Plus with UltraSnap ATP swabs.