Transmission of malaria from vertebrate host to mosquito is mediated by the mature sexual stages of the
Plasmodium life cycle—male and female gametocytes. Gametocytes sense their uptake into the mosquito midgut by a decrease in temperature and the presence of mosquito-derived xanthurenic acid and rapidly differentiate into male and female gametes [
1]. Gametes fuse and fertilization ensues, with the resultant motile ookinetes migrating to and through the midgut epithelium, where they develop into oocysts upon contacting the basal lamina. Artificial feeding of mosquitoes using gametocyte-infected blood in a membrane feeding system is a mainstay of
Plasmodium transmission stage research to study cell biology, vaccine and anti-malarial drug development [
2‐
4]. At its simplest, membrane feeding requires a gametocyte-containing blood meal, a source of heat to maintain the blood at 37 °C (to ensure gametocytes are not prematurely activated and to simulate body temperature to promote mosquito feeding) and a membrane around the blood to simulate the skin of the host [
5]. Two solutions are commonly employed to perform the Standard Membrane Feeding Assay (SMFA): (1) Hemotek
® [
6], in which infected blood is placed between electrically heated feeder reservoirs and a surrounding membrane. (2) Water-jacketed glass or plastic feeders in which heated water from a circulating water bath passes through the feeder and warms the infected blood sample surrounded with a membrane [
7]. This type of glass feeder is most commonly applied in field settings [
8] using a standardized protocol [
5]. Whilst both are effective, they can be expensive for laboratories with limited resources and can only be obtained from a few suppliers, thus limiting their availability.
3D-printing refers to any process using computer control to create a three-dimensional object. The 3D-printing revolution has opened up professional design and manufacture on a small-scale to mainstream users, enabling rapid transitions from an initial design to the finished product. Presented here is a simple two-piece water-jacketed membrane feeder designed to hold a volume of 500 µl. The design for the feeder used here is supplied in OBJ format (Additional files
1 and
2), which can be opened in any computer-aided design (CAD) package for 3D-printing—many of which are provided for free download on the Internet. Using the files presented here, the feeder can be 3D-printed directly and inexpensively by stereolithography by any equipped lab or commercial 3D-printing provider. Alternatively, by using a CAD package the size of the feeder can be up- or downscaled to hold more or less volume respectively.
This study validates and compares the acrylic resin 3D-printed feeder to a conventional glass feeder. Exflagellation rates as well as oocyst counts indicate that there is no significant difference between the two, within the statistical power given by triplicate SMFAs used as standard by the research community. The design of the feeder is provided here, enabling others to gain inexpensive access to equipment needed to perform SMFAs and making future modifications or improvements to the design straightforward.