1. What is ET50?

ET50 (Time at 50% response) is the time point at which a response reaches 50% of its maximum value. It is commonly used in pharmacological and biological studies to quantify the timing of responses.

2. How Does the Calculator Work?

The calculator uses linear interpolation between data points:

Where:

• \( x_1, y_1 \) — Time and percent of point below 50%
• \( x_2, y_2 \) — Time and percent of point above 50%

Explanation: The calculator finds the two data points that bracket the 50% response level and calculates the exact time using linear interpolation.

3. Importance of ET50 Calculation

Details: ET50 provides a standardized measure for comparing response times across different experiments and conditions. It's particularly useful in drug response studies and kinetic analyses.

4. Using the Calculator

Tips: Enter time-percent data pairs separated by commas, with each pair on a new line. Ensure you have at least two data points that bracket the 50% response level for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What format should the data be in?
A: Enter time and percentage values separated by commas, with each data pair on a separate line (e.g., "0, 0" or "5, 25").

Q2: What if my data doesn't bracket 50%?
A: The calculator requires at least one data point below and one above 50% to perform interpolation. If your data doesn't bracket 50%, ET50 cannot be calculated.

Q3: Can I use this for response curves?
A: Yes, ET50 is commonly used to characterize response curves in various scientific fields including pharmacology and biology.

Q4: How accurate is linear interpolation?
A: Linear interpolation provides good accuracy when data points are closely spaced. For more complex curves, nonlinear interpolation methods may be more appropriate.

Q5: What units does ET50 use?
A: ET50 uses the same time units as your input data (seconds, minutes, hours, etc.).