Biophysical Journal 13: 1014-1029 (1973)
© 1973 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nadelhaft, I. Search for Related Content PubMed PubMed Citation Articles by Nadelhaft, I.

Measurement of the Size Distribution of Zymogen Granules from Rat Pancreas

ABSTRACT

Zymogen granules are obtained in pure form and processed for electron microscopy. Thin sections are photographed and diameters measured with a Zeiss particle size analyzer. Since sectioning cuts any given particle in random way, these diameters are not the true diameters of the particles. The true size distribution is obtained by comparing the observed diameter distribution with a generated diameter distribution. The generated distribution is constructed from an assumed parent distribution (of true diameters) by the Monte-Carlo technique. "Goodness of fit" is judged by the value of "chi-squared" resulting from the comparison. Appropriate adjustments of the parameters of the true distribution are made on the basis of minimizing chi-square. A result of this process is that the zymogen granules follow a normal distribution: mean = 0.984 ±0.005 µm, SD = 0.190 ±0.005 µm. A second preparation of granules was made and diameters were measured directly with a scanning electron microscope. The distribution was again found to be normal, thus supporting the first result.

This article has been cited by other articles:

				S. Rothman Protein transport by the pancreas Science, November 21, 1975; 190(4216): 747 - 753. [PDF]