Can Science be separated from Ideology? This topic reminds me of the opening lecture of my scientific methodology course. The professor posed this very question to us and we had a long discussion. Though our reasonings are different, we seemed to reach the consensus that Science and Ideology are not the same, and that they can be and should be separated.
At first glance, Science is strikingly similar to Ideology. Scientists, after all are strong believers and they protect their beliefs with fierceness no less that of the most extreme ideological mindset. The history of Science is full of martyrs who sacrifice everything for their scientific works: Copernicus, Galileo, Harvey to name a few. On the other hand, Ideology by itself is not simply a composition of beliefs that come from nowhere. It has its reasonings and logics, and strong ones (Otherwise it cannot convince anyone). And both Science and Ideology seek to explain the world, and to find Truth (a cynic may say that Ideology just proclaims to do so). From a more "business" aspect, one may claim that Science and Ideology are inherently linked. Scientific works rarely pursue knowledge for knowledge's own sake but to serve a purpose and that purpose can be ultimately traced to Ideology. (By the way, if go to the extreme, any human activity can be traced to one form or another of Ideology).
However, as my dear methodology professor reminds his students countless times, Science is Science and not Ideology because it prioritizes Truth and has place for, even welcomes, doubts and changes. However hard scientists fight for what they believe in, they are the first to tirelessly test those beliefs against hard facts and to forsake them once they are proved wrong. The scientific community does not easily accept (or reject) anything even for their own convenience, as is reflected through the lenghthy and meticulous reviewing process of the scientific journals. Even in the field full of grey areas of social sciences, the boundary between scientific facts proved by evidences and "myths" or personal beliefs are clearly drawn. By contrast, Ideology does not accept challenge and when the facts are against it, it will try to bend them into its established frame. In my impression, Science tries to reveal and preserve the truth always and ever while Ideology just does so when it can benefit from that. I do not think it is not for nothing that the lecture welcoming scientists-to-be in my university is all about the codes-of-conduct of the scientific community which are all about priority for Truth and unending questioning what one encounters (Ironically, this code in itself is idealistic and unyielding thus can be taken as a form of Ideology).
I agree that in practice there is no black and white and that countless time in history scientists have been involved in activities in the domain of Ideology. But then what is the point of having standards and classifications when it is known that nothing perfectly fit in them.