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Fig. 1 | Parasites & Vectors

Fig. 1

From: Identification and validation of a commercial cryopreservation medium for the practical preservation of Dirofilaria immitis microfilaria

Fig. 1

Validation of commercial cryopreservation media for the preservation of D. immitis microfilariae (mf) in vitro. a Comparison of mf motility in vitro for various cryopreservation media. Motility of mf (c.3000 mf/ml) was analyzed on days 0, 1 and 3 post-thawing (dpt) and scored at four levels as follows: inactive or dead (-), less active (+), moderately active (++) and highly active (+++). An asterisk indicates a significant difference (P < 0.05) using Welch’s t-test between the PVP-DMSO control and the other cryopreservation media. Error bars indicate ± standard deviation (SD). b Percent of mf showing positive propidium iodide (PI) staining 3 dpt, indicating dead or dying mf. An asterisk indicates a significant difference based on Chi-square test and adjusted residuals (AR). An absolute value of AR ≥ 1.96 was considered significant (P < 0.05). c Fluorescent images of PI staining of mf 3 dpt (exposure, 200 ms; gain, 0.5). PI image (left) and bright field (BF) image (right). PC, positive control for PI staining fixed by methanol. Scale-bars: 100 µm. d Comparison of mf motility at high (H; c.15,000 mf/ml) and low (L; 3000 mf/ml) concentrations during cryopreservation. Motility was scored at four levels as described in panel a. An asterisk indicates a significant difference (P < 0.05) by Welch’s t-test. Error bars indicate ± SD

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