In this article, I will show how to calculate delta delta CT (Cycle Threshold) in Excel by using 4 easy steps. When you work on an Excel worksheet, you may need to do a variety of work.Â Delta delta CT is a very common expression in Excel works. Delta delta CT is used in Polymerase Chain Reactions (PCR).Â In this article, I will show you four practical steps to calculate delta delta CT in Excel. This will help you to increase your Excel skills.

## What Is Delta Delta CT?

A relative quantification technique is a real-time PCR (Polymerase Chain Reaction). Every study must contain a baseline or calibrator sample to which all other samples are compared as well as at least one endogenous control gene to standardize samples. **CT **(cycle threshold), **dCT **(delta Ct), and **ddCT **are the terms used to express real-time PCR results (delta delta CT). The cycle threshold is the cycle number at which the fluorescence for the reaction well reaches the threshold value (**CT**).

## Calculate Delta Delta CT in Excel: Step-by-Step Procedures

This is the dataset I am going to use in this article for every step. The database contains five columns, **B,** **C**, **D**, **E**, and **F **called Sample, Ct 1, Ct 2 for Housekeeping Gene, and Ct 1, Ct 2 for Gene of Interest. Hence, follow the steps one by one. Moreover, I have added the necessary illustrations for every step for your better understanding.

### Step 1: Getting Average CT

In this step of this article, I will work to get the average ct of my dataset. This is the first step of the procedures to calculate delta delta CT in Excel. Follow the procedures given below.

- First, add two columns in
**E**and**H**called the Average CT of both. The first one is for the Housekeeping Gene and the second one is for the Gene of Interest.

- Then, write down the following formula in cell
**E6**and press**Enter**.

`=AVERAGE(C6:D6)`

We used **the AVERAGE function**Â to get the average of CT 1 and CT 2.

- This
**Enter**command shows the average of Control 1 for Housekeeping Gene. - Then,
**Fill-Handle**to copy down the formula from**E6**to**E11**.

- As a result, this command will show the Average CT of the Housekeeping Gene.

- After that, to get the Average CT of the Gene of Interest, Copy the following formula in the
**H6Â**cellÂ and press**Enter.**

`=AVERAGE(F6:G6)`

The formula will also return the average of CT 1 and CT 2.

- After copying down the formula from
**H6**to**H11**cell, Excel will calculate the Average CT of the Gene of Interest portion.

### Step 2: Calculating Delta CT

In this second part of the procedure of calculating delta delta CT in Excel, I will calculate the delta CT here, Moreover, the average of delta CT will also be calculated here. So follow the procedure step by step patiently.

- First, add a new column in the dataset called delta CT.

- Then, in the
**I6**cell, write down the following formulaÂ and press**Enter.**

`=H6-E6`

We used this formula to get the delta CT.

- Then, press
**Enter**.

- After this command, the delta CT for Control 1 will appear, and the value is
**13.38**.

- Meanwhile, copy down the formula from
**I6**to**I11**.

- Then, I created a new portion to show the average delta CT.

- In the
**I13**cell, write down the following formulaÂ and press**Enter.**

`=AVERAGE(I6:I8)`

We used this function to get the average of **13.38, 13.60, **and **13.68**.

- Then, press
**Enter**.

- As a result of this command, the average delta CT is calculated.

### Step 3: Computing Delta Delta CT

In this third step, I will calculate delta delta CT in Excel. Follow the following procedures. The steps are very easy. Hopefully, you will enjoy it.

- First, add a new column in the
**J**column called delta delta CT.

- Meanwhile, copy down the following formula in the
**J6Â**cellÂ and press**Enter.**

`=I6-$I$13`

This will return the delta delta CT.

- After that, press the
**EnterÂ**button.

- As a result of this operation, you will find the effect of delta delta CT as
**-0.18**.

- After applying flash fill in the
**J**column, Excel will calculate the total result of delta delta CTÂ for every sample.

### Step 4: Final Result

In this section of this article, you can see the final result in the picture below.

- Excel has calculated delta delta CT Â with the help of simple mathematical operators and Excel functions.

Hence, this is how you can calculate delta delta CT in Excel with some easy and simple steps.

## Things to Remember

You should bear in mind that the procedure is lengthy, and a handful of calculations are used. So, be careful at the time of applying formulae.

**Download Practice Workbook**

Please download the workbook to practice yourself.

## Conclusion

In this article, I have tried to explain how to calculate delta delta CT in Excel. I hope you have learned something new from this article. Now, extend your skill by following the steps of these methods.Â I hope you have enjoyed the whole tutorial. If you have any queries, feel free to ask me in the comment section. Donâ€™t forget to give us your feedback.