Live blood cell analysis is more reliable since you get a live visual representation of whats happening in the blood stream; if we can identify and prove that there's live yeast in the fresh blood sample then it will be tough to disprove that, especially by doing a blood culture which can give false info due to the nature of the test. If yeast dies before its cultured whther due to time lapse unfavorable conditions, it does not mean that yeast isn't present in your blood - it just may mean that the test is unreliable.