You refer to original method of Moorhead  et al.(1960) for lymphocyte culture of normal individuals and terminate at 71 hours after adding colcimid at 69 hours.  This is routine method used by every laboratory.  If you use leukemic blood see the count and terminate either by 24 hours or 48 hours without addition of  PHA.  Hope this will serve your purpose.  If you have specific query, do write. Dr.P.K.Gadhia 

Method of Moorhead  et al.(1960) for lymphocyte culture of individuals and terminate at 72 hours after adding colcimid at 69 hours.  This is routine method used by every laboratory

Dear Dian,

in my opinion, the cytokinesis-block micronucleus assay on peripheral

blood lymphocytes is the best method. The micronucleus assay is simpler than other cytogenetics methods because the damaged cytogenetic markers are easy to recognise and score and the results can be obtained in a shorter time. In addition to some cytogenetics markers, information regarding other cellular events such as mitotic rate and cell death by apoptosis and necrosis can be simultaneously obtained from the same slides. This method may be useful for investigating of different genotoxicants (chemical, radiological, and other).

Sincerely,

Maxim Sinitsky

Dear Dian,

Please find attached the recommended procedure by the company that you use their media: it is attached

if you have any questions you know how to contact me

regards

Ahmed