Android : How To preload admob interstitial ad and send to another android activity using intent

I need some help regarding admob interstitial ad.

I want to preload the interstitial ad in one activity. this is straight forward.

// Create an ad.
        interstitialAd = new InterstitialAd(this);
        interstitialAd.setAdUnitId(AD_UNIT_ID);

        AdRequest adRequest = new AdRequest.Builder()
                .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
                .addTestDevice(TEST_DEVICE_ID).build();

        // Load the interstitial ad.
        interstitialAd.loadAd(adRequest);

Now i want to send interstitialAd to another activity using intent. I don't know how to send it using

intent.putExtra("myAd", interstitialAd);

Thanks in advance.