Here you go.

It's 4X concentration. Use it in 1X with your sample and heat (boil) the mixture well to denaturation.

I agree with @jitendra. Making more concentrated sample buffer is just not possible, nor necessary. The difference in detection sensitivity between a 0.75 (4X sample buffer) and a 0.9 (10X sample buffer) dilution is not significant.

(you might buy the buffer if you wish)