Spore suspension

A suspension of spores obtained as described previously (e.g. 1 infected bee ventriculus in 1 ml water; section 2.2.1.) can be filtered using sterile 74 µm sized mesh to remove large pieces of host materials. After filtration, 1-5 mM pH 9.0-buffered ammonium chloride (NH4Cl) can be added to the filtrate to inhibit spore germination. However, sometimes a high purity of spores is needed. Purification can remove unwanted host tissues and microbial contaminants that may confound experimental data, and can also facilitate accurate microscopic counting.