We focus on deoxyribonucleic acid (DNA)-doped liquid crystals and investigate the effect of DNA doping on the molecular alignment structure and electrooptical characteristics for several kinds of DNA molecules such as single and double strands formed by adenine, thymine, guanine and/or cytosine bases. Double strand-DNAs can produce a twist deformation of liquid crystal alignment, while single strand-DNAs cannot. Furthermore, the twisting power is different between the adenine-thymine and guanine-cytosine DNA. As a result of the electrooptical measurement, it has been found that the DNA doping may influence the characteristics such as the response time and threshold voltage.