not a blood test but a dna swab from the inside of your cheeks or saliva can determine if you have male or female chromosomes. if a person has a sex change -- surgically and hormonally challenged -- the chromosomes do not change nor can they be changed. the olympics uses this type of test to determine eligibility to compete.
can gender be determined by a blood test? . in our society today a lot of discussion has been made about sex change operations transgender questions and other social issues. first is male or female able to be determined by a blood test and second if someone wants to change sex can this be achieved by hormones surgery etc.? or can a blood test prove conclusively that someone is a male or female regardless of environmental changes after birth? finally if a blood test can determine sex can this too be changed?