The MiraiBio group of Hitachi Solutions America, Ltd. (HISAL) has partnered with ELISAlink.com to offer ReaderFit.com, a free online curve fitting tool for ELISA analysis, to ELISAlink.com users.

ELISALink.com is an online ELISA community, knowledge base and e-commerce site focused on serving the global ELISA Industry. The site will be anchored by a community-generated ELISA knowledge base and discussion platform and also feature direct access to a wide range of ELISA kits, components, equipment and services.

ReaderFit.com is a free online curve fitting application that allows users to both fit curves and optionally interpolate unknown values off the curve. Users upload response and independent values and then choose from one of 6 model equations: 4PL, 5PL, Quadratic, Log-Logit, Log-Log or Linear and one of four optional weighting algorithms: 1/Y, 1/Y2, 1/X and 1/X2. The resulting curve image and calculated results can then be easily exported from the web application.

“ELISAlink.com is an exciting concept that leverages “web 2.0” and social media features in a way that has been missing in the life science community. People in general have come to expect and rely on some of things that ELISAlink.com offers in other parts of their life. ELISA researchers now have a place to go for all of their ELISA needs. We are excited to offer ReaderFit.com as added value at ELISAlink.com,” said Robert Lynde, Deputy Director of the MiraiBio Group of HISAL.

“The team at HISAL really got it right with ReaderFit. The program is intuitive and designed from the perspective of an ELISA user, providing a streamlined and easy to use platform that is an invaluable tool to researchers and clinical users alike. The powerful Desktop Edition and the 21 CFR Part 11 compliant Security Edition were complimented earlier this year with a completely Online Edition – a natural fit for ELISAlink.com and our mission to provide the best and most powerful ELISA resources on the web,” said David Barka, Founder of ELISAlink.com

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We have been secretly working on moving the desktop version of MasterPlex ReaderFit to the web for all to access….for FREE! This basic version will have limited functionality at first but this will quickly change over time. Towards the end of the year, we will tack on affordable subscription plans for our power users. The basic version will still remain free of course. The core curve-fitting algorithms will be identical to our desktop version but with a slick user interface that takes the complexity out of curve-fitting!

Get an early invitation to use the online version of ReaderFit when it launches!

So when will this be available?
We are planning to unveil the online version of ReaderFit during the Immunology 2011 conference (5/14-5/16) in San Francisco (Moscone Center). Come visit us at booth #219 and see it live!

What would you like to see in this new web version? (Please comment below)

Calculating the EC10 or IC90 values for a dose response curve is not as simple as the EC50 or IC50 values when using the 4PL or 5PL model equations.

The equation for calculating any EC value given a 4PL curve fit is the following:

EC_F = (F/(100-F))^(1/H) * EC₅₀

0 < F < 100 (This is the EC value you are interested in. For example, F=10 for EC₁₀.)
H = Hill Slope for the 4PL curve fit

Luckily, our latest release of MasterPlex ReaderFit 2010 makes this easy. Yes, even with the 5PL curve-fit!

Here’s how:

1. Copy & paste your data into ReaderFit

   Copy your response values from the source and paste it into ReaderFit via CTRL+V -> Paste Response Values.

2. Mark data as Sample Curve type (part 1)

   Select all of the data points that will be used to fit one entire dose response curve including all replicates. In the example given below, there are 7 groups each done in duplicate.
   

3. Mark data as Sample Curve type (part 2)

   Click on the blue Mark Sample Curve button. (The Auto Fill dialog may pop up. Click the Close button if you see it.)
   

4. Indicate known dose concentration values (part 1)

   Select Independent Values(X-axis) from the data pull-down menu. This will show the corresponding data in the plate view. By default, all of the Independent Values(X-axis) will be 0.
   

5. Indicate known dose concentration values (part 2)

   Select the sample of interest and double-click the lower-cell to enter edit mode. Once in edit mode, type in the concentration value. Make sure all values have the same unit. We will edit that later.
   

6. Fitting the curve (part 1)

   Select the Fit Curves tab.
   

7. Fitting the curve (part 2)

   Select either the Four Parameter Logistic (4PL) or Five Parameter Logistic (5PL) from the Curve Fitting section and press the Calculate button.
   

8. Edit dose response curve axes

   Right-click on the dose response curve chart and edit the x and y axes. You also have the option to add a chart title.
   

9. Calculate EC or IC(Anything) value (part 1)

   Press the Statistics Toolbar button.

10. Calculate EC or IC(Anything) value (part 2)

    By default the EC50 and the log EC50 values are calculated for you. If you have an inhibition curve, press the ICxx radio button to switch to IC50 and log IC50 values.
    

11. Calculate EC or IC(Anything) value (part 3)

    If you have an inhibition curve and you are interested in the IC90 calculation, simply select the ICxx radio button and enter “90” into the Percentages section and press the Add button.
    

If you have not done so yet, I would like to invite you to try the free 14-day trial of MasterPlex ReaderFit.