The authors would like to thank Mr Ronnachai Sanmai, Mr Kongkrit Sriburin, Mr Rerngsak Sarakam,
Ms Ruja Datchaipitak and Ms Pornthip Rungruang, the fourth year medical technology students of Rangsit University, for their technical help. This project was financially supported by Rangsit University and Faculty of Medical Technology, Mahidol University, Thailand