Microscopic analysis procedure – a brief outline

Authentic specimen (standard reference material) can be purchased from authorities or prepared by an experienced individual. Note that ontogenetic, geographic, and climate differences may affect the morphological characteristics. 

The client sample has to be representative. A reasonable amount of the sample should be retained for recheck purposes.

Certain steps of clean up may help to mount a clear slide. For samples with a high starch content, heat a small amount of the powdered sample in water in a test tube, rinse it with water, and discard the upper layer. Repeat this several times if necessary. It will help to get rid of the obscured vision field from the starch and fine particles of the sample.

Take a small amount of a powder sample onto a slide and add a couple of drops of a reagent. Put the cover glass on top of the slide. Tip off excess reagent from an edge of the cover by using a tissue paper.

Click to see microscopic reagents and their common usages.

Observe and record the characteristics of the sample, compared to the authentic specimen or authoritative technical descriptions of established microscopic characteristics. See General Guidance for Microscopic Analysis for more details.

More about microscopic analysis

Necessary information should be acquired about the sample which will be analyzed by microscopic identification. This may include source and specification of the raw material and proportion of the ingredient in a multi-components formulation. Noting the processing procedure of a finished product may also be helpful.

Preliminary organoleptic examination will narrow down the range of possibilities in many cases. An experienced individual is capable of identifying a great number of raw materials just by performing organoleptic examinations.

A suitable preparation of the material for a microscopic analysis is as much important as the examination itself. Some times multi-samples prepared from different procedures are required in order to reach a precise conclusion.

Unlike many other analytical methods, microscopic identification does not require sophisticated equipment and chemicals. A set of functioning microscopes and accessories will do most of the job right. For a better data archiving and reporting system, a mounted digital camera with the appropriate software are helpful. A digital system also speeds up the turnaround time.

Every analytical method, whether it’s identification or quantification, has its limits and uncertainties. One of the ways to resolve uncertainties that arise from microscopic analysis is to test the sample with other analytical methods.