Please check this thread: https://www.researchgate.net/post/How_to_prepare_dried_DNA_lyophilized_without_using_any_sophisticated_device_Just_simple_method
Remember, any non-volatile substances (salts, buffer) present in your sample will still be there after lyophilization. If the lyophilized sample is then dissolved in a smaller volume than it was originally, the concentration of these substances will be increased proportionally to the reduction in volume.