The use of photograms provides a permanent record of microbiological assays in which diffusion of a substance in agar is measured. The accuracy of this procedure is comparable to direct measurement. This technique is inexpensive, does not require special photographic equipment, and is applicable to many tests commonly employed in clinical microbiology and immunology laboratories.
References
Am J Med Technol. 1975 Mar;41(3):99-105
[PMID: 1090163]
Am J Clin Pathol. 1975 Aug;64(2):271-2
[PMID: 1155389]
