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. **Delta delta CT** is a very common expression in Excel works. **Delta delta CT **is used in Polymerase Chain Reactions (PCR). 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.

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## 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**).

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

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** 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
**H6**cell 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.

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### 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 formula 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 formula 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.

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### 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
**J6**cell and press**Enter.**

`=I6-$I$13`

This will return the **delta delta CT**.

- After that, press the
**Enter**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 CT**for every sample.

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### 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**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 your mind that the procedure is quite lengthy and a handful amount of calculations are used. So, be careful at the time of applying formulae.

## 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. You will find such interesting blogs on our website **Exceldemy.com**. I hope you have enjoyed the whole tutorial. If you have any queries, feel free to ask me in the comment section. Don’t forget to give us your feedback.